Particulate materials and methods of forming same

ABSTRACT

A particulate material having a body including a first phase having at least about 70 wt % alumina for a total weight of the first phase, and a second phase comprising phosphorus, wherein the body includes at least about 0.1 wt % of the second phase for the total weight of the body, and wherein the second phase has an average grain size of not greater than about 1 micron.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present application is a continuation of U.S. Non-Provisional patentapplication Ser. No. 14/143,656, filed Dec. 30, 2013, entitled“PARTICULATE MATERIALS AND METHODS OF FORMING SAME,” naming inventorsTracy H. Panzarella, Doruk O. Yener, Michael D. Kavanaugh, and Alan J.Brandes, which claims priority from U.S. Provisional Patent ApplicationNo. 61/747,948, filed Dec. 31, 2012, entitled “PARTICULATE MATERIALS ANDMETHODS OF FORMING SAME,” naming inventors Tracy H. Panzarella, Doruk O.Yener, Michael D. Kavanaugh, and Alan J. Brandes, which application isincorporated by reference herein in its entirety.

BACKGROUND

Field of the Disclosure

The following is directed to particulate materials, such as, particulatematerials including a first phase and a second phase, and methods offorming a particulate material.

Description of the Related Art

Abrasive particles and abrasive articles made from abrasive particlesare useful for various material removal operations including grinding,finishing, and polishing. Depending upon the type of abrasive material,such abrasive particles can be useful in shaping or grinding a widevariety of materials and surfaces in the manufacturing of goods. Certaintypes of abrasive particles have been formulated to date that haveparticular geometries, such as triangular shaped abrasive particles andabrasive articles incorporating such objects. See, for example, U.S.Pat. Nos. 5,201,916; 5,366,523; and 5,984,988.

Three basic technologies that have been employed to produce abrasiveparticles having a specified shape are (1) fusion, (2) sintering, and(3) chemical ceramic. In the fusion process, abrasive particles can beshaped by a chill roll, the face of which may or may not be engraved, amold into which molten material is poured, or a heat sink materialimmersed in an aluminum oxide melt. See, for example, U.S. Pat. No.3,377,660, disclosing a process comprising the steps of flowing moltenabrasive material from a furnace onto a cool rotating casting cylinder,rapidly solidifying the material to form a thin semisolid curved sheet,densifying the semisolid material with a pressure roll, and thenpartially fracturing the strip of semisolid material by reversing itscurvature by pulling it away from the cylinder with a rapidly drivencooled conveyor.

In the sintering process, abrasive particles can be formed fromrefractory powders having a particle size of up to 10 micrometers indiameter. Binders can be added to the powders along with a lubricant anda suitable solvent, e.g., water. The resulting mixtures, mixtures, orslurries can be shaped into platelets or rods of various lengths anddiameters. See, for example, U.S. Pat. No. 3,079,242, which discloses amethod of making abrasive particles from calcined bauxite materialcomprising the steps of (1) reducing the material to a fine powder, (2)compacting under affirmative pressure and forming the fine particles ofsaid powder into grain sized agglomerations, and (3) sintering theagglomerations of particles at a temperature below the fusiontemperature of the bauxite to induce limited recrystallization of theparticles, whereby abrasive grains are produced directly to size.

Chemical ceramic technology involves converting a colloidal dispersionor hydrosol (sometimes called a sol), optionally in a mixture, withsolutions of other metal oxide precursors, to a gel or any otherphysical state that restrains the mobility of the components, drying,and firing to obtain a ceramic material. See, for example, U.S. Pat.Nos. 4,744,802 and 4,848,041.

Still, there remains a need in the industry for improving performance,life, and efficacy of abrasive particles, and the abrasive articles thatemploy abrasive particles.

SUMMARY

According to one aspect, a method of making a particulate materialincludes providing a raw material powder, including an additive to theraw material powder, and forming a particulate material having a bodyincluding a first phase comprising an oxide and a second phasecomprising elements of the additive including phosphorus and a rareearth element, wherein the second phase is substantially uniformlydistributed throughout the body.

According to another aspect, a particulate material includes a bodyincluding a first phase having at least about 70 wt % alumina for atotal weight of the first phase, and a second phase comprisingphosphorus, wherein the body comprises at least about 0.1 wt % of thesecond phase for the total weight of the body, and wherein the secondphase has an average grain size of not greater than about 1 micron.

In yet another aspect, a particulate material has a body including afirst phase comprising alumina and a second phase comprising phosphorusand a rare earth element, wherein the second phase is non-uniformlydispersed throughout the body, and wherein the first phase has anaverage grain size of not greater than about 10 microns.

For another aspect, a material includes a body including a first phasecomprising alumina and a second phase comprising phosphorus and a rareearth element, wherein the second phase is substantially uniformlydispersed throughout the body.

According to yet another aspect, an abrasive particulate material has abody including a first phase comprising alpha alumina and a second phasecomprising monazite (LaPO₄), wherein the monazite is disposed betweengrains of alumina, and wherein the second phase is substantiallyuniformly dispersed throughout the body.

For yet another aspect, a batch of particulate material has at least onepredetermined classification characteristic, wherein each of theparticulate material of the batch has a body including a first phasecomprising alpha alumina and a second phase comprising phosphorus.

In one aspect, a shaped abrasive particle has a body including a firstphase and a second phase comprising monazite (LaPO₄).

In one particular aspect, an abrasive article includes a bond materialand an abrasive particulate material having a body including a firstphase comprising alumina and a second phase comprising phosphorous,wherein the second phase is substantially uniformly distributedthroughout the body.

Still, in yet another aspect, a particulate material has a bodyincluding a first phase and a second phase comprising monazite (LaPO₄),wherein the second phase is disposed between grains of the first phase.

For another aspect, a particulate material has a body including a firstphase comprising alumina and a second phase comprising phosphorus,wherein the second phase is disposed between domains of the first phase.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure may be better understood, and its numerousfeatures and advantages made apparent to those skilled in the art byreferencing the accompanying drawings.

FIG. 1 includes a flowchart illustrating a process of forming aparticulate material in accordance with an embodiment.

FIG. 2A includes an illustration of a body of a particulate materialhaving a second phase substantially uniformly dispersed within the bodyaccording to an embodiment.

FIG. 2B includes an illustration of a particulate material having asecond phase non-uniformly dispersed within the body according to anembodiment.

FIG. 2C includes an illustration of a particulate material including asecond phase non-uniformly dispersed within the body according to anembodiment.

FIG. 3A includes a perspective view illustration of an abrasive particlein accordance with an embodiment.

FIG. 3B includes a cross-sectional illustration of the abrasive particleof FIG. 3A.

FIG. 4 includes a side view of a shaped abrasive particle according toan embodiment.

FIG. 5 includes an abrasive article including particulate materialaccording to an embodiment.

FIGS. 6-11 include exemplary particulate materials defining shapedabrasive particles according to an embodiment.

FIGS. 12A-12B include SEM pictures of a particulate material accordingto an embodiment.

FIG. 13 includes a plot of specific grinding energy versus cumulativematerial removed for a comparative grinding test between conventionalparticles and particulate material representative of an embodiment.

FIG. 14 includes a SEM picture of a particulate material according to anembodiment.

FIG. 15 includes a SEM picture of a particulate material according to anembodiment.

FIG. 16 includes a SEM picture of a particulate material according to anembodiment.

FIG. 17 includes a plot of specific grinding energy versus cumulativematerial removed for a grinding test on samples representative ofembodiments herein.

DETAILED DESCRIPTION

The following is directed to methods of forming a particulate materialhaving certain compositions, including a particulate material in theform of abrasive particles, shaped abrasive particles, and the like. Theparticulate material may be used in various articles, including forexample, abrasive articles, including for example, fixed abrasives, suchas bonded abrasive articles, coated abrasive articles, and the like.

FIG. 1 includes a flowchart illustrating a process of forming aparticulate material in accordance with an embodiment. As illustrated,the process can be initiated at step 101, by providing a raw materialpowder. In at least one embodiment, the raw material powder can be amaterial selected from the group of oxides, carbides, nitrides, borides,oxycarbides, oxynitrides, oxyborides, and combination thereof. Incertain instances, the raw material powder may include an oxide.Furthermore, the raw material powder may include alumina, and mayconsist essentially of alumina. In one embodiment, the raw materialpowder may include a hydrated alumina. In another embodiment, the rawmaterial powder may include alpha alumina.

As noted herein, the raw material powder can included a seeded material,such as material processed through a seeded processing pathway. That is,for example, the raw material may be include a seed material, which maybe a compound, complex, or element configured to control the growth ofparticular crystalline phases within the raw material powder. The seededraw material powder may include a minority content of seed material,which may facilitate the formation of particular crystalline phasesduring further processing of the raw material powder. One non-limitingseeded processing pathway is described herein. In other instances, theraw material powder may include an unseeded material, and can beessentially free of seed material.

Providing a raw material powder can include synthesis of a particulatematerial by obtaining an aluminous raw material. While certain aluminousraw materials can be sourced commercially, in other instances, thealuminous raw material may be manufactured. In accordance with anembodiment, the process of forming can include processes such as,dispersing, mixing, gelling, seeding, calcining, shaping, printing,molding, extruding, pressing, drying, crushing, sieving, sorting, and acombination thereof.

As noted herein, the raw material powder may be obtained bymanufacturing the powder, including for example, manufacturing analuminous raw material according to a seeded pathway. In one embodiment,the aluminous raw material can include a boehmite precursor and boehmiteseeds in a suspension (alternatively sol or slurry), that can beheat-treated (such as by hydrothermal treatment) to convert the boehmiteprecursor into boehmite particulate material formed of particles orcrystallites. The term “boehmite” is generally used herein to denotealumina hydrates including mineral boehmite, typically being Al2O3.H2Oand having a water content on the order of 15%, as well aspseudoboehmite, having a water content higher than 15%, such as 20-38%by weight. It is noted that boehmite (including pseudoboehmite) has aparticular and identifiable crystal structure, and accordingly uniqueX-ray diffraction pattern, and as such, is distinguished from otheraluminous materials including other hydrated aluminas such as ATH(aluminum trihydroxide) a common precursor material used herein for thefabrication of boehmite particulate materials.

After forming suitable boehmite particulate material, a heat treatmentprocess can be carried out to effect polymorphic transformation, whichremoves water and forms an alumina material. According to one aspect,the boehmite particulate material can have a relatively elongatedmorphology, described generally herein in terms of primary (and alsosecondary and tertiary) aspect ratio and described in more detail below,and the morphology of the boehmite is largely preserved in the feedstockparticulate material.

Primary aspect ratio is defined as the ratio of the longest dimension tothe next longest dimension perpendicular to the longest dimension and isgenerally not less than 2:1, and preferably not less than 3:1, 4:1, or6:1. With particular reference to needle-shaped particles, the particlesmay be further characterized with reference to a secondary aspect ratiodefined as the ratio of the second longest dimension to the thirdlongest dimension. The secondary aspect ratio is generally not greaterthan 3:1, typically not greater than 2:1, or even 1.5:1, and oftentimesabout 1:1. The secondary aspect ratio generally describes thecross-sectional geometry of the particles in a plane perpendicular tothe longest dimension. It is noted that since the term aspect ratio isused herein to denote the ratio of the longest dimension to the nextlongest dimension, it may be referred as the primary aspect ratio.

Alternatively, the boehmite particulate material can have a platey orplatelet-shaped contour, generally have an elongated structure havingthe primary aspect ratios described above in connection with theneedle-shaped particles. However, platelet-shaped particles generallyhave opposite major surfaces, the opposite major surfaces beinggenerally planar and generally parallel to each other. In addition, theplatelet-shaped particles may be characterized as having a secondaryaspect ratio greater than that of needle-shaped particles, generally notless than about 3:1, such as not less than about 6:1, or even not lessthan 10:1.

The morphology of the boehmite particulate material formed through aseeding process can have a relatively fine particle or crystallite size.Generally, the average boehmite material particle size is not greaterthan about 1000 nanometers, and fall within a range of about 100 to 1000nanometers. Other embodiments have even finer average particle sizes,such as not greater than about 800 nanometers, 750 nanometers, 600nanometers, 500 nanometers, 400 nanometers, and even particles having anaverage particle size smaller than 300 nanometers, representing a fineparticulate material. As used herein, the “average particle size” inconnection with high aspect ratio boehmite particulate material is usedto denote the average longest or length dimension of the particles.

In addition to aspect ratio and average particle size of the boehmiteparticulate material, morphology of the boehmite particulate materialmay be further characterized in terms of specific surface area. Here,the commonly available BET technique was utilized to measure specificsurface area of the boehmite particulate material. According toembodiments herein, the boehmite particulate material may have arelatively high specific surface area, generally not less than about 10m2/g, such as not less than about 50 m²/g, 70 m²/g, or not less thanabout 90 m²/g. Since specific surface area is a function of particlemorphology as well as particle size, generally the specific surface areaof embodiments was less than about 400 m²/g, such as less than about 350or 300 m²/g. Specific ranges for surface area are about 75 m²/g to 200m²/g.

Turning to the details of the processes by which the seeded boehmiteparticulate material may be manufactured, generally ellipsoid, needle,or platelet-shaped boehmite are formed from a boehmite precursor,typically an aluminous material including bauxitic minerals, byhydrothermal treatment as generally described in the commonly ownedpatent described above, U.S. Pat. No. 4,797,139. More specifically, theboehmite particulate material may be formed by combining the boehmiteprecursor and boehmite seeds in suspension, exposing the suspension(alternatively sol or slurry) to heat treatment to cause conversion ofthe raw material into boehmite particulate material, further influencedby the boehmite seeds provided in suspension. Heating is generallycarried out in an autogenous environment, that is, in an autoclave, suchthat an elevated pressure is generated during processing. The pH of thesuspension is generally selected from a value of less than 7 or greaterthan 8, and the boehmite seed material can have a particle size finerthan about 0.5 microns. Generally, the seed particles are present in anamount greater than about 1% by weight of the boehmite precursor(calculated as Al₂O₃), and heating is carried out at a temperaturegreater than about 120° C., such as greater than about 125° C., or evengreater than about 130° C., and at a pressure that is autogenouslygenerated, typically around 30 psi.

Following heat treatment, such as by hydrothermal treatment, andboehmite conversion, the liquid content is generally removed, such asthrough an ultrafiltration process or by heat treatment to evaporate theremaining liquid. Thereafter, the resulting mass is generally crushed,such as to 100 mesh. It is noted that the particulate size describedherein generally describes the individual particles formed throughprocessing, rather than the aggregates which may remain in certainembodiments (e.g., for those products that call for an aggregatedmaterial).

Certain processing variables may be modified during the formation of theboehmite particulate material, to affect the desired morphology. Thesevariables include the weight ratio, that is, the ratio of boehmiteprecursor to boehmite seed, the particular type or species of acid orbase used during processing (as well as the relative pH level), and thetemperature (which is directly proportional to pressure in an autogenoushydrothermal environment) of the system.

Suitable acids and bases include mineral acids such as nitric acid,organic acids such as formic acid, halogen acids such as hydrochloricacid, and acidic salts such as aluminum nitrate and magnesium sulfate.Effective bases include, for example, amines including ammonia, alkalihydroxides such as potassium hydroxide, alkaline hydroxides such ascalcium hydroxide, and basic salts.

After forming the boehmite particulate material, which can be the rawmaterial powder used in later processes according to embodiments herein,the process can further include heat-treatment of the boehmiteparticulate material to form an aluminous material. In accordance with aparticular embodiment, the heat-treatment can include calcination of theboehmite particulate material at a temperature sufficient to causetransformation into a particular phase of alumina (e.g., gamma, delta,theta, alpha) or combination of phases of alumina providing a suitablealuminous material. For purposes of clarification, an aluminous materialis one that comprises a majority content (wt %) of alumina (Al2O3) andpreferably, at least about 80 wt %, at least 90 wt %, at least 95 wt %or even consisting essentially of alumina. Still, the boehmiteparticulate material may be used for other processes beforeheat-treatment, including for example the provision of an additive,which is described in more detail herein.

Referring again to FIG. 1, after step 101 and providing a raw material,the process can continue at step 103 by including an additive to the rawmaterial powder. In accordance with an embodiment, the process ofincluding an additive can include an impregnation process, which mayinclude providing the additive into pores of the raw material powder.The porosity of the raw material powder may be obtained through naturalor artificial processes. For example, the raw material powder may firstbe processed through other techniques, such as calcining to facilitatethe formation of a porous raw material powder, and thereafter, theadditive may be added to the raw material powder to facilitateimpregnation. Still, as will be described herein, one or more processesmay be utilized before or after calcination to facilitate inclusion ofan additive.

In certain instances, the process of impregnating can include saturationof the porosity of the raw material powder with the additive. Saturationcan include filling at least a portion of the pore volume of the rawmaterial powder with the additive. Still, a saturation process mayinclude filling a majority of the porosity with the additive, and moreparticularly, may include filling substantially all of the total porevolume of the raw material powder with the additive. The saturationprocess, which may further include an over-saturation process, canutilize processes including, but not limited to, soaking, mixing,stirring, increased pressure above atmospheric conditions, decreasedpressure below atmospheric conditions, particular atmospheric conditions(e.g., inert atmosphere, reducing atmosphere, oxidizing atmosphere),heating, cooling, and a combination thereof. In at least one particularembodiment, the process of including can include soaking the rawmaterial powder in a solution containing the additive.

In certain instances, the additive can include more than one component.For example, the additive may include a first component and a secondcomponent distinct from the first component. In accordance with anembodiment, the first component may include a rare earth element, andmore particularly, a compound including at least one rare earth element.According to certain embodiments, the first component may include asalt, and may be present as a solution including the rare earth element.For example, the first component may include a nitrate salt solution. Inone particular embodiment, the rare earth element may include lanthanum(La), and more particularly, may include lanthanum nitrate.

As noted above, the additive can include a second component distinctfrom the first component. For example, the second component may includean element such as phosphorous. In addition, the second component may bepresent as a compound including phosphorous. For certain embodiments,the second component can include a solution comprising phosphorous. Somesuitable solutions can include an acid, which can have a pH less thanabout 7, a base, which can have a pH of greater than about 7, oralternatively a neutral solution. In one particular instance, the secondcomponent can include hydrogen, and more particularly, may be present asphosphoric acid (H₃PO₄).

The process of including the additive can include particularcombinations of the first component and the second component into theraw material powder. For example, in one embodiment, the process ofincluding the additive can include providing the first component at afirst time and the second component at a second time. The first time andsecond time may be the same as each other, such that the first componentand second component can be added to the raw material powdersimultaneously. Still, in another embodiment, the first component andsecond component can be added to the raw material powder at differenttimes. For example, the first component may be added before the secondcomponent. Alternatively, the first component may be added after thesecond component.

The process of including an additive can include performing at least oneprocess between the addition of the first component and the addition ofthe second component to the raw material powder. For example, someexemplary processes that may be conducted between the addition of thefirst component and the second component can include mixing, drying,heating, calcining and a combination thereof. In one particularembodiment, the process of including the additive may include providingthe first component to the raw material powder, heating the raw materialpowder after the addition of the first component to the raw materialpowder, and providing the second component to the raw material powderand first component after heating the raw material and first component.It will be appreciated that such a heating process may include acalcining process.

The process of calcination can include heating the raw material powderto a temperature suitable to remove particular volatile components andfacilitate the formation of a porous raw material. In one particularinstance, the process of calcining can be conducted at a temperature ofat least about 300° C. In other instances, the calcining temperature maybe greater, such as at least about 600° C., at least about 700° C., oreven at least about 750° C. Still, the process of calcining may beconducted at a temperature not greater than about 1200° C., such as notgreater than about 1000° C. or even not greater than about 900° C. Itwill be appreciated that the process of calcining can be conducted at atemperature within a range between any of the minimum and maximum valuesnoted above.

According to alternative embodiment, the process of including anadditive can include a process of doping. Doping can include a processwherein the additive is combined with the raw material powder prior toconducting certain processes, particularly calcination of the rawmaterial powder. The doping process may also utilize an additiveincluding a first component and a second component, according toembodiments herein. In particular, the first component and secondcomponent may both be added to the raw material powder prior to acalcination process.

Referring again to FIG. 1, after completing the process of including anadditive to the raw material powder at step 103, the process cancontinue at step 105 by forming a particulate material. The particulatematerial may include a body having a first phase comprising an oxide andsecond phase comprising at least one element of the additive, includingfor example, phosphorous, a rare earth element, and a combinationthereof.

The process of forming can include combining the first component andsecond component of the additive to form a precursor of the second phasepresent within the particulate material. In at least one embodiment, theprocess of forming can include a reaction of the additive, and moreparticularly, may include a chemical reaction between at least anelement of the first portion of the additive and at least one element ofthe second portion of the additive to form a chemical product in theform of the precursor of the second phase. For example, in one instance,the precursor of the second phase can include a hydrated compound, moreparticularly, a compound including phosphorous and the rare earthelement, and even more particularly, the precursor of the second phasemay include rhabdophane (La)PO₄.(H₂O), which can include a hydrated formof a compound including at least one rare earth element and phosphate.

In accordance with an embodiment, the process of forming can furtherinclude converting the precursor of the second phase to a second phase.In one embodiment, the process of converting the precursor of the secondphase to a second phase can include the application or alteration of atleast one of temperature, pressure, atmosphere, and a combinationthereof. Converting the precursor of the second phase to a second phasecan include volatilization of certain species, including for example,water. Moreover, the process of converting can include crystallizationor a change in crystalline structure of the precursor of the secondphase. In still another embodiment, the process of converting caninclude densification.

According to a particular embodiment, the process of converting theprecursor of the second phase to the second phase can include firing theraw material and precursor of the second phase. The firing process mayinclude a sintering process, including densification of the material andformation of high temperature phases of the first phase, including forexample, alpha alumina. Firing may be conducted at a temperature of atleast about 500° C., such as at least about 700° C., or even at leastabout 800° C. Still, firing may be conducted at a temperature that isnot greater than about 1200° C., such as not greater than 1100° C., oreven not greater than about 1000° C. It will be appreciated that firingmay be conducted at a temperature within a range between any of theabove minimum and maximum temperatures.

Furthermore, it will be appreciated that sintering may be conducted fora particular time and under a particular atmosphere. For example,sintering may be conducted for at least about 1 minute at ambientconditions, or even at least about 4 minutes, at least about one hour,such as at least about two hours, or even at least about three hours.Furthermore, the atmosphere utilized during sintering may include anoxidizing atmosphere, a reducing atmosphere, or an inert atmosphere.

In accordance with an embodiment, after conducting the forming process,the particulate material can have a density of at least about 95%theoretical density. In other instances, the particulate material mayhave a greater density, such as at least about 96% or even at leastabout 97% theoretical density.

After conducting the forming process the particulate material may have aspecific surface area of not greater than about 100 m²/g. In still otherembodiments, the specific surface area of the particulate material maybe not greater than about 90 m²/g, such as not greater than 80 m²/g, oreven not greater than about 10 m²/g, or even not greater than about 1m²/g. Still, the specific surface area of the particulate material maybe at least about 0.01 m²/g, or even at least about 0.05 m²/g. It willbe appreciated that the specific surface area of the particulatematerial may be be within a range between any of the above minimum andmaximum values.

In yet another embodiment, the particulate material can have a bodyhaving an average particle size, which may be selected from a group ofpredetermined sieve sizes. For example, the body can have an averageparticle size of not greater than about 5 mm, such as not greater thanabout 3 mm, not greater than about 2 mm, not gather than about 1 mm, oreven not greater than about 0.8 mm. Still, in another embodiment, thebody may have an average particle size of at least about 0.1 μm. It willbe appreciated that the body may have an average particle size within arange between any of the minimum and maximum values noted above.

Particles for use in the abrasives industry are generally graded to agiven particle size distribution before use. Such distributionstypically have a range of particle sizes, from coarse particles to fineparticles. In the abrasive art this range is sometimes referred to as a“coarse”, “control”, and “fine” fractions. Abrasive particles gradedaccording to abrasive industry accepted grading standards specify theparticle size distribution for each nominal grade within numericallimits. Such industry accepted grading standards (i.e., abrasiveindustry specified nominal grade) include those known as the AmericanNational Standards Institute, Inc. (ANSI) standards, Federation ofEuropean Producers of Abrasive Products (FEPA) standards, and JapaneseIndustrial Standard (JIS) standards.

ANSI grade designations (i.e., specified nominal grades) include: ANSI4, ANSI 6, ANSI 8, ANSI 16, ANSI 24, ANSI 36, ANSI 40, ANSI 50, ANSI 60,ANSI 80, ANSI 100, ANSI 120, ANSI 150, ANSI 180, ANSI 220, ANSI 240,ANSI 280, ANSI 320, ANSI 360, ANSI 400, and ANSI 600. FEPA gradedesignations include P8, P12, P16, P24, P36, P40, P50, P60, P80, P100,P120, P150, P180, P220, P320, P400, P500, P600, P800, P1000, and P1200.JIS grade designations include JIS8, JIS12, JIS16, JIS24, JIS36, JIS46,JIS54, JIS60, JIS80, JIS100, JIS150, JIS180, JIS220, JIS240, JIS280,JIS320, JIS360, JIS400, JIS600, JIS800, JIS1000, JIS 1500, JIS2500,JIS4000, JIS6000, JIS8000, and JIS10,000. Alternatively, the shapedabrasive particles 20 can graded to a nominal screened grade usingU.S.A. Standard Test Sieves conforming to ASTM E-11 “StandardSpecification for Wire Cloth and Sieves for Testing Purposes.” ASTM E-11prescribes the requirements for the design and construction of testingsieves using a medium of woven wire cloth mounted in a frame for theclassification of materials according to a designated particle size. Atypical designation may be represented as −18+20 meaning that theparticles pass through a test sieve meeting ASTM E-11 specifications forthe number 18 sieve and are retained on a test sieve meeting ASTM E-11specifications for the number 20 sieve. In various embodiments, theparticulate material can have a nominal screened grade comprising:−18+20, −20/+25, −25+30, −30+35, −35+40, −40+45, −45+50, −50+60, −60+70,−70/+80, −80+100, −100+120, −120+140, −140+170, −170+200, −200+230,−230+270, −270+325, −325+400, −400+450, −450+500, or −500+635.Alternatively, a custom mesh size could be used such as −90+100. Thebody of the particulate material may be in the form of a shaped abrasiveparticle, as described in more detail herein.

In accordance with an embodiment, the first phase may include alumina,such as alpha alumina, and more particularly, may consist essentially ofalpha alumina. In certain instances, the body may be formed such that itis not greater than about 1 wt % of low-temperature alumina phases. Asused herein, low temperature alumina phases can include transition phasealuminas, bauxites or hydrated alumina, including for example gibbsite,boehmite, diaspore, and mixtures containing such compounds and minerals.Certain low temperature alumina materials may also include some contentof iron oxide. Moreover, low temperature alumina phases may includeother minerals, such as goethite, hematite, kaolinite, and anastase. Inparticular instances, the particulate material can consist essentiallyof alpha alumina as the first phase and may be essentially free of lowtemperature alumina phases.

Furthermore, the particulate material may be formed such that the bodyincludes not greater than about 1 wt % of impurity elements. Someexemplary impurity elements can include transition metal elements,alkaline earth elements, alkaline elements, and a combination thereof.In one particular instance, the body can include a limited amount ofwater, such as a content within the body of not greater than about 1 wt% water for the total weight of the body. Moreover, the body can beessentially free of water.

In one aspect, the particulate material may have a body including afirst phase having at least about 70 wt % alumina for a total weight ofthe first phase. For other embodiments, the body can include at leastabout 71 wt % alumina for the total weight of the first phase, such asleast about 75 wt %, at least about 77 wt %, at least about 80 wt %, atleast about 83 wt %, at least about 85 wt %, at least about 88 wt %, atleast about 90 wt %, at least about 93 wt %, at least about 95 wt %, oreven consist essentially of alumina.

Furthermore, the particulate material can have a body including at leastabout 70 wt % of the first phase for the total weight of the body. Inother instances, the total content of the first phase may be greater,such as at least about 75 wt %, at least about 77 wt %, at least about80 wt %, at least about 83 wt %, at least about 85 wt %, at least about88 wt %, at least about 90 wt %, at least about 93 wt % or even at leastabout 95 wt % for the total weight of the body. Still, the body mayinclude not greater than about 99.5 wt %, not greater than about 99 wt%, or even not greater than about 98 wt % of the first phase for thetotal weight of the body. It will be appreciated that the total contentof the first phase within the body can be within a range between any ofthe minimum and maximum percentages noted above.

In yet another embodiment, the particulate material can include a firstphase having grains defining crystallites having an average grain sizeof not greater than about 500 μm. Still, in other instances, the averagegrain size of the first phase may be not greater than about 250 μm, suchas not greater than about 100 μm, not greater than about 50 μm, or evennot greater than about 1 μm. Still, in at least one embodiment, thefirst phase may have an average grain size of at least about 1 nm. Itwill be appreciated that the average grain size of the first phase canbe within a range between any of the minimum and maximum values notedabove.

As noted herein, the body can further include a second phase. Forcertain particulate materials according to embodiments herein, the bodycan consist essentially of the first phase and the second phase. In oneinstance, the body can include at least 0.1 wt % of the second phase forthe total weight of the body. For other embodiments, the content of thesecond phase within the body can be greater, such as at least about 0.2wt %, at least about 0.3 wt %, at least about 0.5 wt %, at least about0.6 wt %, at least about 0.7 wt %, at least about 0.9 wt %, at leastabout 1.0 wt %, or even at least about 1.1 wt %. Still, the content ofthe second phase within the body may be limited, such that it may be notgreater than about 30 wt %, such as not greater than about 20 wt %, notgreater than about 15 wt %, not greater than about 13 wt %, not greaterthan about 12 wt %, not greater than about 10 wt %, not greater thanabout 9 wt %, not greater than about 8 wt %, not greater than about 7 wt%, not greater than about 6 wt %, not greater than about 5 wt %, notgreater than about 4 wt %, not greater than about 3 wt %, or even notgreater than about 2 wt %. It will be appreciated that the content ofthe second phase within the body can be within a range between any ofthe minimum and maximum percentages noted above.

The second phase can be distinct from the first phase by at least one ofaverage grain size, composition, content, crystal structure, and acombination thereof. In certain instances, the second phase can includea rare earth element, and more particularly, a lanthanoid. Some suitableexamples of rare earth elements can include materials such as La, Ce,Pr, Nd, Pm, Sm, and a combination thereof. For certain embodiments, therare earth element can include lanthanum, and more particularly, mayconsist essentially of lanthanum. The second phase may consistessentially of a single rare earth element. The second phase may beessentially free of certain elements, such as Ce, Nd, Sm, and acombination thereof.

In accordance with an embodiment, the second phase can include an oxide.Furthermore, the second phase may include phosphate. In particularinstances, the second phase may include a majority content of phosphateand at least one rare earth element. For example, the second phase canconsist essentially of phosphate and at least one rare earth element,and more particularly may consist essentially of monazite (LaPO₄).Furthermore, the second phase may consist essentially of a crystallinematerial. Moreover, the second phase may include a crystalline materialhaving a monoclinic crystalline structure. For example, the second phasecan consist essentially of a crystalline phase, and further, can consistessentially of a monoclinic crystalline structure.

In accordance with one embodiment, the body can include a ratio (W1/W2),wherein W1 represents the weight percent of the first phase of the bodyand W2 represents the weight percent of the second phase within thebody. In at least one aspect, the ratio (W1/W2), can be at least about1, such as at least about 1.1, at least about 1.5, at least about 2, atleast about 3, at least about 5, at least about 8, at least about 10, atleast about 15, at least about 20, at least about 50, or even at leastabout 70. Still, in another embodiment the ratio (W1/W2) can be notgreater than about 100, or even not greater than about 95. It will beappreciated that the body can have a ratio (W1/W2) within a rangebetween any of the minimum and maximum values provided above.

The particulate material can have a body that includes a particularratio of size of grains of the first phase and second phase. Forexample, the body can include a first phase having a first average grainsize and a second phase having a second average grain size. In certaininstances, the second average grain size of the second phase can be lessthan the first average grain size of the grains of the first phase.Moreover, in at least one aspect, the body can have a ratio (G1/G2)wherein G1 represents the average grain size of the first phase and G2represents the average grain size of the second phase. In accordancewith a particular embodiment, the ratio (G1/G2) can be at least about1.1, such as at least about 1.5, at least about 2, at least about 3, atleast about 5, at least about 8, at least about 10, at least about 15, aleast about 20, or even at least about 50. Still, in at least oneembodiment, the ratio (G1/G2) may be not greater than about 500, such asnot greater than about 200, or even not greater than about 100. It willbe appreciated that the body can include a ratio (G1/G2) within a rangebetween any of the above minimum and maximum values.

In one embodiment, the body can include a second phase having an averagegrain size of not greater than 500 μm. In other instances, the averagegrain size of the second phase may be less, such as not greater thanabout 250 μm, not greater than about 100 μm, not greater than about 50μm, not greater than about 1 μm, not greater than about 0.8 μm, notgreater than about 0.5 μm, or even not greater than about 0.2 μm. Still,the average grain size of the second phase may be at least about 1 nm,such as at least about 0.01 μm or even at least about 0.1 μm. It will beappreciated that the second phase can have an average grain size withina range between any of the minimum and maximum values noted above.

The second phase can be disposed within domains or between domains ofany of the other phases present within the body. A domain can include asingle crystal or a group of crystals having the same or substantiallythe same alignment when viewed in two dimensions. In one embodiment, thesecond phase may be disposed at the grain boundaries of any of the otherphases, and more particularly, a majority of the second phase may bedisposed as an intergranular phase (i.e., between grains at the grainboundaries) between any of the phases described in embodiments herein.For example, at least 60% of the total content of the second phase canbe disposed at the grain boundaries of the first phase. In otherembodiments, the amount of second phase disposed at the grain boundariescan be greater, such as at least about 70% of the second phase, at leastabout 80% of the second phase, at least about 90% of the second phase,or even in some instances essentially all of the second phase can bedisposed at the grain boundary of the first phase.

In yet another embodiment, the second phase may be disposed within thegrains of any of the other phases present within the body, and moreparticularly, a majority of the second phase can be disposed as anintragranular phase (i.e., within the grains) within any of the grainsof any of the phases described in embodiments herein. For example, amajority of the second phase can be disposed within the grains ordomains of the first phase.

In yet another embodiment, the second phase may have a particularmorphology. For example, in certain instances, the second phase can havea certain shape as viewed in two-dimensions (e.g., using SEM), includingfor example, but not limited to, equiaxed, elongated, elliptical,needle-like, irregular, or the like. In one particular embodiment, thesecond phase can have an elongated morphology, including an aspect ratioof length:width of at least about 1.5:1, wherein length is the longestdimension of the second phase as viewed in two-dimensions and the widthis a dimension extending perpendicular to the length and defining adimension shorter than the length. For other embodiments, the aspectratio of length:width of the second phase can be at least about 1.8:1,at least about 2:1, at least about 2.5:1, at least about 3:1, or even atleast about 5:1. It will be appreciated, that such morphology can applyto any of the phases present within the body of the particulate materialin the embodiments herein.

In accordance with an embodiment, the body can be formed to have aparticular distribution of the second phase within the volume of thebody. For example, second phase may be an integral phase within thebody. Moreover, the second phase may be substantially uniformlydispersed through the entire volume of the body. FIG. 2A includes anillustration of particulate material including a second phasesubstantially uniformly dispersed within the body. As illustrated, theparticulate material 200 includes a particle having a body 201 that canbe formed of a first phase 202 and a second phase 203. The body 201 canbe made primarily of the first phase 202, and the second phase 203 canbe present in a minority content compared to the first phase 202. Asfurther illustrated, the second phase 203 can be substantially,uniformly dispersed throughout the volume of the body 201, such that ifa statistically relevant and random sampling of different portions ofthe body 201 was obtained, the content of the second phase 203 betweeneach of the different samplings would be substantially the same. Incertain embodiments, the variation of the second phase, which may bebased upon a standard deviation, may be not greater than about 20% ofthe average value of the second phase for the body, as calculated by theequation (AVG/STDEV)×100%, wherein AVG represents the average content ofthe second phase for each of the different portions and STDEV representsthe standard deviation of the content of the second phase for thesampling.

Alternatively, the second phase may be non-uniformly dispersed withinthe body. For example, in one embodiment, the body can have a differentcontent of the second phase at a peripheral region of the body ascompared to a content of the second phase at a central region of thebody. In certain instances, the body can have a greater content of thesecond phase at the peripheral region of the body as compared to thecontent of the second phase at a central region. In another embodiment,the body may have a greater content of the second phase at an exteriorsurface as compared to a central region of the body. Still, in onealternative embodiment, the content of the second phase may be greaterat a central region as compared to the content of the second phase at aperipheral region.

FIG. 2B includes an illustration of particulate material including asecond phase non-uniformly dispersed within the body. As illustrated,the particulate material 210 can include a particle having a body 211that can be formed of a first phase 202 and a second phase 203. Thesecond phase 203 can be non-uniformly dispersed throughout the volume ofthe body 211. In particular, the body 211 can include a greater contentof the second phase 203 within a peripheral region 213 as compared tothe content of the second phase 203 within the central region 215. Insuch instances, the second phase 213 appears to create a “halo” in thebody 211. The peripheral region 213 of the body 211 can extend from theexterior surface 212 into the volume of the body 211 for a distance thatencompasses at least a majority of the second phase 203. In particularinstances, the peripheral region 213 can be defined by the regionencompassing at least about 90% of the second phase between the exteriorsurface 212 and a boundary 214 between the exterior surface 212 and thevolumetric midpoint 216 of the body. For example, the peripheral region213 may include at least about 5%, such as at least about 10%, at leastabout 20%, or even at least about 25% of the total volume of the body.The central region 215 of the body 211 may be a region surrounding thevolumetric midpoint 216 of the body and extending out in threedimensions to a boundary 214. The central region may be at least about5%, such as at least about 10%, at least about 20% or even at leastabout 25% of the total volume of the body. The above illustration is notlimiting, and it will be appreciated that various particles may be madeto form a peripheral region and a central region of different sizes andshapes.

Moreover, it will be appreciated that the second phase can bedistributed in other non-uniform manners throughout the volume of a bodyof particulate material. For example, FIG. 2C includes an illustrationof particulate material including a second phase non-uniformly dispersedwithin the body according to an embodiment. As illustrated, theparticulate material 220 can include a particle having a body 221 thatcan be formed of a first phase 202 and a second phase 203. The secondphase 203 can be non-uniformly dispersed throughout the body 221, and inparticular, the content of the second phase can be greatest at theexternal surface 222, within the body 221 and the content of the secondphase can decrease with increasing distance from the external surface222 toward the volumetric midpoint 226 within the body 221. Moreover, incertain instances, the body 221 of the particulate material can havethin regions 225, wherein the volume of the body 221 is less compared toa thick region 227. According to one embodiment, in conditions ofnon-uniform distribution of the second phase 203, the thin region 225can have a greater concentration (i.e., amount of second phase per unitvolume) of the second phase 203 as compared to the concentration of thesecond phase 203 within a thick region 227.

It will be appreciated that foregoing embodiments describing certaindistributions of the second phase within the body can be the same forother phases of the particulate material. For example, as will bedescribed in more detail herein, the particulate material can includeadditional phases distinct from the first and second phases (e.g., athird phase, a fourth phase, a fifth phase, etc.), and such phases canbe substantially uniformly dispersed through the volume of the body, oralternatively, may be distributed in a non-uniform manner. For example,in one embodiment, the particulate material can include a body having anon-uniform distribution of a second phase and a third phase within thevolume of the body. More particularly, the body can have a greatercontent of the second phase at a peripheral region compared to a centralregion, and the body may also have a greater content of the third phaseat the central region compared to the peripheral region. Still, in otherinstances, the body can include multiple phases having differentdistribution characteristics. For example, the second phase may besubstantially, uniformly distributed throughout the volume of the bodyand a third phase may be non-uniformly distributed throughout the body.

In certain embodiments, the body may further include a third phase thatcan be distinct from the first phase and the second phase by at leastone of average grain size, composition, content, crystal structure, anda combination thereof. For example, the third phase may include a singlerare earth element. The rare earth element of the third phase may be thesame as the rare earth element of the second phase. Still, in analternative embodiment, the rare earth element of the third phase may bedifferent that the rare earth element of the second phase. According toat least one embodiment herein, the particulate material can include abody that consists essentially of the first phase, second phase, andthird phase. Other alternative particulate material according toembodiments herein can include a body consisting essentially of thefirst phase, second phase, third phase, and a fourth phase. In yet otherinstances, the body can consist essentially of the first phase, secondphase, a third phase, and a fifth phase.

The third phase may be an integral phase within the body. Moreover, thethird phase may be substantially uniformly dispersed through the entirevolume of the body. Alternatively, the third phase may be non-uniformlydispersed within the body, including for example, but not limited to,disposed in a “halo” manner as described in embodiments herein.Additionally, the third phase can be disposed within domains or betweendomains of any of the other phases present within the body. In yetanother embodiment, the third phase may be disposed at the grainboundaries of any of the other phases, and more particularly, a majorityof the third phase may be disposed as an intergranular phase (i.e.,between grains at the grain boundaries) between any of the phasesdescribed in embodiments herein. Alternatively, the third phase can bedisposed within the grains of any of the other phases present within thebody, and more particularly, a majority of the third phase can bedisposed as an intragranular phase (i.e., within the grains) within anyof the grains of any of the phases described in embodiments herein.

The third phase may include an oxide, such as alumina, and moreparticularly a combination of alumina and a rare earth element. In oneparticular instance, the third phase may include lanthanum aluminate(LaAl₁₁O₁₈), or lanthanum aluminate compounds (e.g., MgLaAl₁₁O₁₉).Still, the third phase can consist essentially of lanthanum aluminate ora lanthanum aluminate compound.

In certain instances, the particulate material includes a body having aparticular ratio (W1/W3), wherein W1 represents the weight percent ofthe first phase of the body and W3 represents the weight percent of thethird phase within the body. In at least one aspect, the ratio (W1/W3),can be at least about 1, such as at least about 1.1, at least about 1.5,at least about 2, at least about 3, at least about 5, at least about 8,at least about 10, at least about 15, at least about 20, at least about50, or even at least about 70. Still, in another embodiment the ratio(W1/W3) can be not greater than about 100, or even not greater thanabout 95. It will be appreciated that the body can have a ratio (W1/W3)within a range between any of the minimum and maximum values providedabove.

Furthermore, in another aspect, the particulate material can include abody having a ratio (W3/W2), wherein W2 represents a weight percent ofthe second phase with the body and W3 represents a weight percent of thethird phase within the body. In particular instances, the ratio (W3/W2)can be at least about 0.1, such as at least about 0.3, at least about0.5, at least about 0.7, at least about 0.9, at least about 1, at leastabout 1.1, at least about 1.5, at least about 2, at least about 4, atleast about 6, or even at least about 10. Still, in yet anotherembodiment, the body can have a ratio (W3/W2) that is not greater thanabout 10, for example, not greater than about 7, not greater than about5, not greater than about 3, not greater than about 2.5, not greaterthan about 2.2, not greater than about 2, not greater than about 1.5,not greater than about 1, not greater than about 0.9, or even notgreater than about 0.7. It will be appreciated that the ratio (W3/W2)can be within a range between any of the above minimum or maximumvalues.

The body may be formed to have a particular content of the third phasefor the total weight of the body. For example, the body may include atleast about 0.1 wt % of the third phase for the total weight of thebody. In other instances, the body may include a greater content of thethird phase, such as at least about 0.2 wt %, at least about 0.3 wt %,at least about 0.5 wt %, at least about 0.6 wt %, at least about 0.7 wt%, at least about 0.8 wt %, at least about 0.9 wt %, at least about 1 wt%, or even at least about 1.1 wt % for the total weight of the body.Still, in another embodiment, the particulate material can be formedsuch that the body includes not greater than about 30 wt % of the thirdphase for the total weight of the body. In other instances, the contentof the third phase within the body can be less, such as not greater thanabout 20 wt %, not greater than about 15 wt %, not greater than about 13wt %, not greater than about 12 wt %, not greater than about 10 wt %,not greater than about 9 wt %, not greater than about 8 wt %, notgreater than about 7 wt %, not greater than about 6 wt %, not greaterthan about 4 wt %, not greater than about 3 wt %, or even not greaterthan about 2.5 wt %. It will be appreciated that the body can include acontent of the third phase within a range between any of the minimum andmaximum percentages noted above.

In accordance with another aspect, the particulate material can beformed such that the average grain size of the third phase has aparticular relationship to the average grain size of the first phase andthe second phase. For example, the particulate material can include abody having a first phase including a first average grain size and athird phase having a third average grain size. In certain instances, thefirst phase can have a first average grain size that is different thanthe third average grain size of the third phase. More particularly, thebody can include a ratio (G1/G3) wherein G1 represents the average grainsize of the first phase and G3 represents the average grain size of thethird phase. In at least one instance, the ratio (G1/G3) can be notgreater than about 5, such as not greater than about 2, not greater thanabout 1, not greater than about 0.8, not greater than about 0.5, or evennot greater than about 0.2. Still, in another embodiment, the ratio(G1/G3) can be at least about 0.2, such as at least about 0.5, at leastabout 0.8, at least about 1, at least about 1.1, at least about 1.5, atleast about 2, or even at least about 3. It will be appreciated that theratio (G1/G3) can have a value within a range between any of the minimumor maximum values noted above.

For certain embodiments, the second phase can have a second averagegrain size that is different than the third average grain size of thethird phase, and more particularly, may be less than the third averagegrain size of the third phase. In at least one instance, the body canhave a ratio (G2/G3) wherein G2 represents the second average grain sizeof the second phase and G3 represents the third average grain size ofthe third phase. The ratio (G2/G3) can be at least about 0.2, such as atleast about 0.5, at least about 0.8, at least about 1, at least about1.1, at least about 1.5, at least about 2, or even at least about 3.Still, in accordance with another embodiment, the ratio (G2/G3) may notbe greater than about 3, such as not greater than about 2, not greaterthan about 1, not greater than about 0.8, not greater than about 0.5, oreven not greater than about 0.2. It will be appreciated that the ratio(G2/G3) can be within a range between any of the minimum and maximumvalues note above.

The body can include a third phase having an average grain size of notgreater than 500 μm. In other instances, the average grain size of thethird phase may be less, such as not greater than about 250 μm, notgreater than about 100 μm, not greater than about 50 μm, not greaterthan about 1 μm, not greater than about 0.8 μm, not greater than about0.5 μm, or even not greater than about 0.2 μm. Still, the average grainsize of the third phase may be at least about 0.1 μm, at least about atleast about 1 μm, at least about 3 μm, at least about 5 μm, or even atleast about 10 μm. It will be appreciated that the third phase can havean average grain size within a range of the minimum and maximum valuesnoted above.

In accordance with yet another embodiment, the particulate material maybe formed such that the body includes a fourth phase. The fourth phasecan be distinct from the first phase, second phase and/or the thirdphase. The fourth phase may be distinct from the first phase, secondphase, and third phase by at least one of an average grain size,composition, content, crystal structure, and a combination thereof. Thefourth phase may be an integral phase within the body. Moreover, thefourth phase may be substantially uniformly dispersed through the entirevolume of the body. Alternatively, the fourth phase may be non-uniformlydispersed within the body, including for example, but not limited to,disposed in a “halo” manner as described in embodiments herein.Additionally, the fourth phase can be disposed within domains or betweendomains of any of the other phases present within the body. The fourthphase may be disposed at the grain boundaries of any of the otherphases, and more particularly, a majority of the fourth phase may bedisposed as an intergranular phase (i.e., between grains at the grainboundaries) between any of the phases described in embodiments herein.Alternatively, the fourth phase can be disposed within the grains of anyof the other phases present within the body, and more particularly, amajority of the fourth phase can be disposed as an intragranular phase(i.e., within the grains) within any of the grains of any of the phasesdescribed in embodiments herein.

Certain embodiments herein can include a particulate material having abody consisting essentially of the first phase, second phase, and thefourth phase. Other alternative particulate material according toembodiments herein can include a body consisting essentially of thefirst phase, second phase, third phase, and fourth phase. In yet otherinstances, the body can consist essentially of the first phase, secondphase, fourth phase, and a fifth phase.

In accordance with one embodiment, the fourth phase can include aninorganic material, such as an oxide, and more particularly, a metaloxide compound. The fourth phase may include a transition metal element,and more particularly, may include chromium. In accordance with oneparticular embodiment, the fourth phase can include chromium oxide, andmay consist essentially of chromium oxide.

The body may include a particular content of the fourth phase. Forexample, in at least one embodiment, the body can include at least 0.2wt % of the fourth phase for the total weight of the body. In otherinstances, the content of the fourth phase within the body may begreater, such as at least about 0.3 wt %, at least about 0.5 wt %, atleast about 0.7 wt %, at least about 0.8 wt %, at least about 0.9 wt %,at least about 1.0 wt %, or even at least about 1.1 wt %. Still, thecontent of the fourth phase within the body may be not greater thanabout 20 wt %, such as not greater than about 15 wt %, not greater thanabout 10 wt %, not greater than about 8 wt %, not greater than about 5wt %, not greater than about 4 wt %, not greater than about 3 wt %, notgreater than about 2.5 wt %, or even not greater than about 2 wt %. Itwill be appreciated that the total content of the fourth phase withinthe body may be within a range between any of the minimum and maximumvalues noted above.

In accordance with one embodiment, the body can contain a particularamount of the fourth phase with respect to the content of the firstphase. For example, the body can include a ratio (W1/W4), wherein W1represents a weight percent of the first phase within the body and W4represents a weight percent of the fourth phase within the body. Inaccordance within an embodiment, the ratio (W1/W4) can be at least about1, such as at least about 1.1, at least about 1.5, at least about 2, atleast about 3, at least about 5, at least about 8, at least about 10, atleast about 15, at least about 20, at least about 50, or even at leastabout 70. Still, the ratio (W1/W4) may be not greater than about 100, oreven not greater than about 95. It will be appreciated that the ratio(W1/W4) may have a value within a range between any of the above minimumand maximum values.

In accordance with an embodiment, the particulate material may be formedsuch that the body comprises a particular content of the fourth phaserelative to the content of the second phase. For example, the body canhave ratio (W4/W2), wherein W2 represents a weight percent of the secondphase with the body and W4 represents a weight percent of the fourthphase within the body. In accordance with an embodiment, the ratio(W4/W2) can be about 0.1, such as at least about 0.3, at least about0.5, at least about 0.7, at least about 0.9, at least about 1, or evenat least about 1.1. In yet another embodiment, the ratio (W4/W2) may benot greater than about 10, such as not greater than about 7, not greaterthan about 5, not greater than about 3, not greater than about 2, notgreater than about 1, or even not greater than about 0.8. It will beappreciated that the ratio (W4/W2) can be within a range between any ofthe above minimum or maximum values.

Furthermore, the body can have a particular ratio of the content of thethird phase relative to a content of the fourth phase. For example, thebody can include a ratio (W3/W4), wherein W3 represents a weight percentof the third phase within the body and W4 represents a weight percent ofthe fourth phase within the body. In accordance within an embodiment,the ratio (W3/W4) can be at least about 1, such as at least about 1.1,at least about 1.5, at least about 2, at least about 3, at least about5, at least about 8, at least about 10, at least about 15, at leastabout 20, at least about 50, or even at least about 70. Still, the ratio(W3/W4) may be not greater than about 100, or even not greater thanabout 95, not greater than about 80, not greater than about 50, notgreater than about 30, not greater than about 10, not greater than about5, not greater than about 3, not greater than about 2, not greater thanabout 1, or even not greater than about 0.8. It will be appreciated thatthe ratio (W3/W4) may have a value within a range between any of theabove minimum and maximum values.

In accordance with another aspect, the particulate material can beformed such that the average grain size of the fourth phase has aparticular relationship to the average grain size of the first phase,second phase, and/or the third phase. For example, the particulatematerial can include a body having a first phase including a firstaverage grain size and a fourth phase having a fourth average grainsize. In particular instances, the first phase can have a first averagegrain size that is different than the fourth average grain size of thefourth phase. More particularly, the body can include a ratio (G1/G4),wherein G1 represents the average grain size of the first phase and G4represents the average grain size of the fourth phase. In at least oneinstance, the ratio (G1/G4) can be not greater than about 5, such as notgreater than about 2, not greater than about 1, not greater than about0.8, not greater than about 0.5, or even not greater than about 0.2.Still, in another embodiment, the ratio (G1/G4) can be at least about0.2, such as at least about 0.5, at least about 0.8, at least about 1,at least about 1.1, at least about 1.5, at least about 2, or even atleast about 3. It will be appreciated that the ratio (G1/G4) can have avalue within a range between any of the minimum or maximum values notedabove.

The second phase can have a second average grain size that is differentthan the fourth average grain size of the fourth phase, and moreparticularly, may be less than or greater than the fourth average grainsize of the fourth phase. In at least one instance, the body can have aratio (G2/G4), wherein G2 represents the second average grain size ofthe second phase and G4 represents the fourth average grain size of thefourth phase. The ratio (G2/G4) can be at least about 0.2, such as atleast about 0.5, at least about 0.8, at least about 1, at least about1.1, at least about 1.5, at least about 2, or even at least about 3.Still, in accordance with another embodiment, the ratio (G2/G4) may notbe greater than about, such as not greater than about 2, not greaterthan about 1, not greater than about 0.8, not greater than about 0.5, oreven not greater than about 0.2. It will be appreciated that the ratio(G2/G4) can be within a range between any of the minimum and maximumvalues note above.

The third phase can have a third average grain size that is differentthan the fourth average grain size of the fourth phase, and moreparticularly, may be greater than or less than the fourth average grainsize of the fourth phase. In at least one instance, the body can have aratio (G3/G4), wherein G3 represents the third average grain size of thethird phase and G4 represents the fourth average grain size of thefourth phase. The ratio (G3/G4) can be at least about 0.2, such as atleast about 0.5, at least about 0.8, at least about 1, at least about1.1, at least about 1.5, at least about 2, or even at least about 3.Still, in accordance with another embodiment, the ratio (G3/G4) may notbe greater than about, such as not greater than about 2, not greaterthan about 1, not greater than about 0.8, not greater than about 0.5, oreven not greater than about 0.2. It will be appreciated that the ratio(G3/G4) can be within a range between any of the minimum and maximumvalues note above.

For particulate material having a body including a fourth phase, thebody may have a particular average grain size of the fourth phase. Forexample, the average grain size of the fourth phase can be not greaterthan 500 μm. In other instances, the average grain size of the fourthphase may be less, such as not greater than about 250 μm, not greaterthan about 100 μm, not greater than about 50 μm, not greater than about1 μm, not greater than about 0.8 μm, not greater than about 0.5 μm, oreven not greater than about 0.2 μm. Still, the average grain size of thefourth phase may be at least about 1 nm, such as at least about 0.01 μm,at least about 0.1 μm, at least about at least about 1 μm, at leastabout 3 μm, at least about 5 μm, or even at least about 10 μm. It willbe appreciated that the fourth phase can have an average grain sizewithin a range of the minimum and maximum values noted above.

In accordance with an embodiment, the particulate material can include abody having a fifth phase. The fifth phase may be distinct from thefirst phase, second phase, third phase, and fourth phase by at least oneof an average grain size, content, composition, crystal structure, and acombination thereof. The fifth phase may be an integral phase within thebody. Moreover, the fifth phase may be substantially uniformly dispersedthrough the entire volume of the body. Alternatively, the fifth phasemay be non-uniformly dispersed within the body, including for example,but not limited to, disposed in a “halo” manner as described inembodiments herein. Additionally, the fifth phase can be disposed withindomains or between domains of any of the other phases present within thebody. In yet another embodiment, the fifth phase may be disposed at thegrain boundaries of any of the other phases, and more particularly, amajority of the fifth phase may be disposed as an intergranular phase(i.e., between grains at the grain boundaries) between any of the phasesdescribed in embodiments herein. Alternatively, the fifth phase may bedisposed as an intragranular phase (i.e., within the grains) within anyof the grains of any of the phases described in embodiments herein, andmore particularly, a majority of the fifth phase may be present as anintragranular phase.

Furthermore, it will be appreciated that reference to any of the phasesin any embodiment does not require the existence of the all the phasesto be present. For example, the fifth phase may be present within thebody without the existence of the third phase and/or fourth phase.Certain embodiments herein can include a particulate material having abody consisting essentially of the first phase, second phase, and thefifth phase. Other particulate material according to embodiments hereincan include a body consisting essentially of the first phase, secondphase, third phase, and fifth phase. In yet other instances, the bodycan consist essentially of the first phase, second phase, fourth phase,and the fifth phase.

The body can include a fifth phase that may include phosphorous, andmore particularly, a compound including phosphate (PO₄). In at least oneembodiment, the fifth phase can include a compound includingphosphorous, and at least one element of the group of alumina, chromium,and any combination thereof. In another embodiment, the fifth phase mayinclude free phosphate. Moreover, the fifth phase may be formed of acompound that is essentially free of a rare earth element.

The body may include a particular content of the fifth phase. Forexample, in at least one embodiment, the body can include at least 0.2wt % of the fifth phase for the total weight of the body. In otherinstances, the content of the fifth phase within the body may begreater, such as at least about 0.3 wt %., at least about 0.5 wt %, atleast about 0.7 wt %, at least about 0.8 wt %, at least about 0.9 wt %,at least about 1.0 wt %, or even at least about 1.1 wt %. Still, thecontent of the fifth phase within the body may be not greater than about20 wt %, such as not greater than about 15 wt %, not greater than about10 wt %, not greater than about 8 wt %, not greater than about 5 wt %,not greater than about 4 wt %, not greater than about 3 wt %, notgreater than about 2.5 wt %, or even not greater than about 2 wt %. Itwill be appreciated that the total content of the fifth phase within thebody may be within a range between any of the minimum and maximum valuesnoted above.

The body may include a specific content of the fifth phase relative toother phases. For example, the body can include a greater content of thefirst phases as compared to the fifth phase. Additionally oralternatively, the body can include a greater content of the secondphases compared to the fifth phase. Moreover, the body may include agreater content of the third phase and or fourth phases compared to thefifth phase.

In accordance with one embodiment, the body can contain a particularamount of the fifth phase with respect to the content of the firstphase. For example, the body can include a ratio (W1/W5), wherein W1represents a weight percent of the first phase within the body and W5represents a weight percent of the fifth phase within the body. Inaccordance within an embodiment, the ratio (W1/W5) can be at least about1, such as at least about 1.1, at least about 1.5, at least about 2, atleast about 3, at least about 5, at least about 8, at least about 10, atleast about 15, at least about 20, at least about 50, or even at leastabout 70. Still, the ratio (W1/W5) may be not greater than about 100, oreven not greater than about 95. It will be appreciated that the ratio(W1/W5) may have a value within a range between any of the above minimumand maximum values.

The particulate material may be formed such that the body comprises aparticular content of the fifth phase relative to the content of thesecond phase. For example, the body can have ratio (W5/W2), wherein W2represents a weight percent of the second phase with the body and W5represents a weight percent of the fifth phase within the body. Inaccordance with an embodiment, the ratio (W5/W2) may be not greater thanabout 10, such as not greater than about 7, not greater than about 3,not greater than about 1, not greater than about 0.8, not greater thanabout 0.5, not greater than about 0.3, or even not greater than about0.1. Still, in at least one embodiment, the ratio (W5/W2) can be atleast about 0.1, such as at least about 0.3, at least about 0.5, atleast about 0.7, at least about 0.9, at least about 1, at least about1.1, at least about 1.5, at least about 2, at least about 3, or even atleast about 5. It will be appreciated that the ratio (W5/W2) can bewithin a range between any of the above minimum or maximum values.

Furthermore, certain particulate material according to an embodimentherein may include a body having a particular ratio of the content ofthe third phase relative to a content of the fifth phase. For example,the body can include a ratio (W3/W5), wherein W3 represents a weightpercent of the third phase within the body and W5 represents a weightpercent of the fifth phase within the body. In accordance within anembodiment, the ratio (W3/W5) can be at least about 1, such as at leastabout 1.1, at least about 1.5, at least about 2, at least about 3, atleast about 5, at least about 8, at least about 10, at least about 15,at least about 20, at least about 50, or even at least about 70. Still,the ratio (W3/W5) may be not greater than about 100, or even not greaterthan about 95, not greater than about 80, not greater than about 50, notgreater than about 30, not greater than about 10, not greater than about5, not greater than about 3, not greater than about 2, not greater thanabout 1, or even not greater than about 0.8. It will be appreciated thatthe ratio (W3/W5) may have a value within a range between any of theabove minimum and maximum values.

In one aspect, a particulate material according to an embodiment hereinmay include a body having a particular ratio of the content of thefourth phase relative to a content of the fifth phase. For example, thebody can include a ratio (W4/W5), wherein W4 represents a weight percentof the fourth phase within the body and W5 represents a weight percentof the fifth phase within the body. In accordance within an embodiment,the ratio (W4/W5) can be at least about 1, such as at least about 1.1,at least about 1.5, at least about 2, at least about 3, at least about5, at least about 8, at least about 10, at least about 15, at leastabout 20, at least about 50, or even at least about 70. Still, the ratio(W4/W5) may be not greater than about 100, or even not greater thanabout 95, not greater than about 80, not greater than about 50, notgreater than about 30, not greater than about 10, not greater than about5, not greater than about 3, not greater than about 2, not greater thanabout 1, or even not greater than about 0.8. It will be appreciated thatthe ratio (W4/W5) may have a value within a range between any of theabove minimum and maximum values.

In accordance with another aspect, the particulate material can beformed such that the average grain size of the fifth phase may have aparticular relationship to the average grain size of the first phase,second phase, third phase, and/or fourth phase. For example, theparticulate material can include a body having a first phase including afirst average grain size and a fifth phase having a fifth average grainsize. In particular instances, the first phase can have a first averagegrain size that is different than the fifth average grain size of thefifth phase. More particularly, the body can include a ratio (G1/G5),wherein G1 represents the average grain size of the first phase and G5represents the average grain size of the fifth phase. In at least oneinstance, the ratio (G1/G5) can be not greater than about 5, such as notgreater than about 2, not greater than about 1, not greater than about0.8, not greater than about 0.5, or even not greater than about 0.2.Still, in another embodiment, the ratio (G1/G5) can be at least about0.2, such as at least about 0.5, at least about 0.8, at least about 1,at least about 1.1, at least about 1.5, at least about 2, or even atleast about 3. It will be appreciated that the ratio (G1/G5) can have avalue within a range between any of the minimum or maximum values notedabove.

For certain embodiments, the second phase can have a second averagegrain size that is different than the fifth average grain size of thefifth phase, and more particularly, may be greater than or less than thefifth average grain size of the fifth phase. In at least one instance,the body can have a ratio (G2/G5), wherein G2 represents the secondaverage grain size of the second phase and G5 represents the fifthaverage grain size of the fifth phase. The ratio (G2/G5) can be at leastabout 0.2, such as at least about 0.5, at least about 0.8, at leastabout 1, at least about 1.1, at least about 1.5, at least about 2, oreven at least about 3. Still, in accordance with another embodiment, theratio (G2/G5) may not be greater than about, such as not greater thanabout 2, not greater than about 1, not greater than about 0.8, notgreater than about 0.5, or even not greater than about 0.2. It will beappreciated that the ratio (G2/G5) can be within a range between any ofthe minimum and maximum values note above.

The third phase can have a third average grain size that is differentthan the fifth average grain size of the fifth phase, and moreparticularly, may be greater than or less than the fifth average grainsize of the fifth phase. In at least one instance, the body can have aratio (G3 /G5), wherein G3 represents the third average grain size ofthe third phase and G5 represents the fifth average grain size of thefifth phase. The ratio (G3/G5) can be at least about 0.2, such as atleast about 0.5, at least about 0.8, at least about 1, at least about1.1, at least about 1.5, at least about 2, or even at least about 3.Still, in accordance with another embodiment, the ratio (G3/G5) may notbe greater than about, such as not greater than about 2, not greaterthan about 1, not greater than about 0.8, not greater than about 0.5, oreven not greater than about 0.2. It will be appreciated that the ratio(G3/G5) can be within a range between any of the minimum and maximumvalues note above.

For certain embodiments, the fourth phase can have a fourth averagegrain size that is different than the fifth average grain size of thefifth phase, and more particularly, may be greater than or less than thefifth average grain size of the fifth phase. In at least one instance,the body can have a ratio (G4/G5), wherein G4 represents the fourthaverage grain size of the fourth phase and G5 represents the fifthaverage grain size of the fifth phase. The ratio (G4/G5) can be at leastabout 0.2, such as at least about 0.5, at least about 0.8, at leastabout 1, at least about 1.1, at least about 1.5, at least about 2, oreven at least about 3. Still, in accordance with another embodiment, theratio (G4/G5) may not be greater than about, such as not greater thanabout 2, not greater than about 1, not greater than about 0.8, notgreater than about 0.5, or even not greater than about 0.2. It will beappreciated that the ratio (G4/G5) can be within a range between any ofthe minimum and maximum values note above.

For particulate material having a body including a fifth phase, the bodymay have a particular average grain size of the fifth phase. Forexample, the average grain size of the fifth phase can be not greaterthan 500 μm. In other instances, the average grain size of the fifthphase may be less, such as not greater than about 250 μm, not greaterthan about 100 μm, not greater than about 50 μm, not greater than about1 μm, not greater than about 0.8 μm, not greater than about 0.5 μm, oreven not greater than about 0.2 μm. Still, the average grain size of thefifth phase may be at least about 1 nm, such as at least about 0.01 μm,at least about 0.1 μm, at least about at least about 1 μm, at leastabout 3 μm, at least about 5 μm, or even at least about 10 μm. It willbe appreciated that the fifth phase can have an average grain sizewithin a range of the minimum and maximum values noted above.

In yet another embodiment, the body can be in the form of a shapedabrasive particle. A shaped abrasive particle can have a body configuredto have a predetermined shape. Shaped abrasive particles may differ fromconventional crushed grains, which generally have an irregular shape.When considered as a batch, shaped abrasive particles can becharacterized by one or more features that may be, but not necessarilyneed be, linked to one or more conditions of forming, such that the oneor more features may be substantially replicated fromparticle-to-particle. Moreover, the one or more features may be evidentwithin at least a majority of the particles in a batch. Conventionalcrushed grains generally have a random shape. Shaped abrasive particlesmay be obtained through various processing methods, including but notlimited to, printing, molding, pressing, stamping, casting, extruding,cutting, fracturing, heating, cooling, crystallizing, rolling,embossing, depositing, etching, scoring, and a combination thereof.

One non-limiting process of forming a shaped abrasive particle can beinitiated by forming a mixture including a ceramic material and aliquid. In particular, the mixture can be a gel formed of a ceramicpowder material and a liquid, wherein the gel can be characterized as ashape-stable material having the ability to substantially hold a givenshape even in the green (i.e., unfired) state. In accordance with anembodiment, the gel can be formed of the ceramic powder material as anintegrated network of discrete particles. The mixture may contain acertain content of solid material, liquid material, and additives suchthat it has suitable rheological characteristics. That is, in certaininstances, the mixture can have a certain viscosity, and moreparticularly, suitable rheological characteristics that form adimensionally stable phase of material that can be formed through theprocess as noted herein. A dimensionally stable phase of material is amaterial that can be formed to have a particular shape and substantiallymaintain the shape, such that the shape is substantially present in thefinally-formed object.

The ceramic powder material can include an oxide, a nitride, a carbide,a boride, an oxycarbide, an oxynitride, and a combination thereof. Inparticular instances, the ceramic material can include alumina. Morespecifically, the ceramic material may include a boehmite material,which may be a precursor of alpha alumina. The mixture can be formed tohave a particular content of solid material, such as the ceramic powdermaterial. For example, in one embodiment, the mixture can have a solidscontent of at least about 25 wt % and not greater than about 75 wt % forthe total weight of the mixture. Furthermore, the mixture 101 can beformed to have a particular content of liquid material, including forexample, a liquid content of at least about 25 wt % and not greater thanabout 75 wt % for the total weight of the mixture 101.

Furthermore, to facilitate processing and forming shaped abrasiveparticles according to embodiments herein, the mixture can have aparticular storage modulus, such as at least about 1×10⁴ Pa, at leastabout 4×10⁴ Pa, or even at least about 5×10⁴ Pa. However, in at leastone non-limiting embodiment, the mixture may have a storage modulus ofnot greater than about 1×10⁷ Pa, such as not greater than about 2×10⁶Pa. It will be appreciated that the storage modulus of the mixture 101can be within a range between any of the minimum and maximum valuesnoted above. The storage modulus can be measured via a parallel platesystem using ARES or AR-G2 rotational rheometers, with Peltier platetemperature control systems. For testing, the mixture 101 can beextruded within a gap between two plates that are set to beapproximately 8 mm apart from each other. After extruding the gel intothe gap, the distance between the two plates defining the gap is reducedto 2 mm until the mixture 101 completely fills the gap between theplates. After wiping away excess mixture, the gap is decreased by 0.1 mmand the test is initiated. The test is an oscillation strain sweep testconducted with instrument settings of a strain range between 01% to100%, at 6.28 rad/s (1 Hz), using 25-mm parallel plate and recording 10points per decade. Within 1 hour after the test completes, lower the gapagain by 0.1 mm and repeat the test. The test can be repeated at least 6times. The first test may differ from the second and third tests. Onlythe results from the second and third tests for each specimen should bereported.

Furthermore, to facilitate processing and forming shaped abrasiveparticles according to embodiments herein, the mixture can have aparticular viscosity. For example, the mixture can have a viscosity ofat least about 4×10³ Pa s, at least about 5×10³ Pa s, at least about6×10³ Pa s, at least about 8×10³ Pa s, at least about 10×10³ Pa s, atleast about 20×10³ Pa s, at least about 30×10³ Pa s, at least about40×10³ Pa s, at least about 50×10³ Pa s, at least about 60×10³ Pa s, atleast about 65×10³ Pa s. In at least one non-limiting embodiment, themixture may have a viscosity of not greater than about 100×10³ Pa s, notgreater than about 95×10³ Pa s, not greater than about 90×10³ Pa s, oreven not greater than about 85×10³ Pa s. It will be appreciated that theviscosity of the mixture can be within a range between any of theminimum and maximum values noted above. The viscosity can be measured inthe same manner as the storage modulus as described above.

Moreover, the mixture can be formed to have a particular content oforganic materials, including for example, organic additives that can bedistinct from the liquid, to facilitate processing and formation ofshaped abrasive particles according to the embodiments herein. Somesuitable organic additives can include stabilizers, binders, such asfructose, sucrose, lactose, glucose, UV curable resins, and the like.

Notably, the process of forming a shaped abrasive particle may utilize amixture that can be distinct from slurries used in conventional formingoperations. For example, the content of organic materials, within themixture, particularly, any of the organic additives noted above, may bea minor amount as compared to other components within the mixture. In atleast one embodiment, the mixture can be formed to have not greater thanabout 30 wt % organic material for the total weight of the mixture.Moreover, the mixture can be formed to have a particular content of acidor base distinct from the liquid, to facilitate processing and formationof shaped abrasive particles according to the embodiments herein. Somesuitable acids or bases can include nitric acid, sulfuric acid, citricacid, chloric acid, tartaric acid, phosphoric acid, ammonium nitrate,ammonium citrate.

Various systems may be used to shape the mixture and form precursorshaped abrasive particles. Still, in one particular embodiment includinga screen printing operation, the mixture can be configured to beextruded through a die opening, and during extrusion within anapplication zone, a screen having a plurality of openings can travelunder the die opening. In accordance with an embodiment, the openingscan have a two-dimensional shape as viewed in a plane defined by thelength (l) and width (w) of the screen that include various shapes, forexample, polygons, ellipsoids, numerals, Greek alphabet letters, Latinalphabet letters, Russian alphabet characters, complex shapes includinga combination of polygonal shapes, and a combination thereof. Inparticular instances, the openings may have two-dimensional polygonalshapes such as, a triangle, a rectangle, a quadrilateral, a pentagon, ahexagon, a heptagon, an octagon, a nonagon, a decagon, and a combinationthereof. The shape of the openings may facilitate substantial formationof one or more features of the shaped abrasive particles.

After forcing the mixture through the die opening and into the openingsin the screen, precursor shaped abrasive particles may be printed on abelt disposed under the screen. During the process of extruding themixture into the openings of the screen the belt may be in contact withthe screen. Alternatively, the belt may be spaced apart from the screen.Notably, the mixture can be forced through the screen in rapid fashion,such that the average residence time of the mixture within the openingscan be less than about 2 minutes, less than about 1 minute, less thanabout 40 second, or even less than about 20 seconds. In particularnon-limiting embodiments, the mixture may be substantially unalteredduring printing as it travels through the screen openings, thusexperiencing no change in the amount of components from the originalmixture, and may experience no appreciable drying in the openings of thescreen.

The precursor shaped abrasive particles may be translated through aseries of zones wherein various treating processes may be conducted.Some suitable exemplary treating processes can include drying, heating,curing, reacting, radiating, mixing, stirring, agitating, planarizing,calcining, sintering, comminuting, sieving, doping, and a combinationthereof. According to one embodiment, the precursor shaped abrasiveparticles may be translated through an optional shaping zone, wherein atleast one exterior surface of the particles may be shaped as describedin embodiments herein. Furthermore, the precursor shaped abrasiveparticles may be translated through an application zone wherein one ormore additives can be applied to the precursor shaped abrasiveparticles, which can be the same process of providing an additive to theraw material powder as described in embodiments herein. Within theapplication zone, the additive material may be applied utilizing variousmethods including for example, spraying, dipping, depositing,impregnating, transferring, punching, cutting, pressing, and anycombination thereof. And further, the precursor shaped abrasiveparticles may be translated on the belt through a post-forming zone,wherein a variety of processes, including for example, drying, firing,sintering may be conducted on the precursor shaped abrasive particles toform shaped abrasive particles.

In accordance with another aspect, the particulate material ofembodiments herein may be part of a batch. A batch of particulatematerial can have at least one predetermined classificationcharacteristic including, but not limited to, average particle size,particle shape, density, specific surface area, hardness, friability,particle color, hardness, friability, toughness, density, specificsurface area, and a combination thereof.

In accordance with one particular embodiment, the batch of particulatematerial can include a first portion comprising a first plurality ofparticulate material and a second portion comprising a second pluralityof particulate material. Notably, the particulate material of the firstplurality may be distinct from the second portion based on one or morepredetermined classification characteristics or other particleparameters. For example, the difference between the first portion andthe second portion may be based upon factors including, but not limitedto, average particle size, composition, size, shape, hardness,friability, toughness, density, specific surface area, and a combinationthereof. In one instance, the first portion can include a particulatematerial having a first content of the second phase including thephosphorous-containing material and the second portion of particulatematerial within the batch can have a second content of the second phaseof material including the phosphorous-containing material that isdifferent than the first content of the second phase material from thefirst portion. Still, in other embodiments, the content of second phasematerial within the first portion and the second portion may besubstantially the same.

In another embodiment, the first portion can include a particulatematerial having a first dispersion of the second phase within each thebodies of the particulate material and the second portion of the batchcan include a particulate material, wherein each particulate materialhas a body having a distribution of the second phase that can bedifferent than the nature of the dispersion of the second phase withinthe first portion. For example, the first portion can include aparticulate material, wherein the body of each particulate materialwithin the first portion has a second phase that can be substantiallyuniformly dispersed throughout the volume of the body. By contrast, thebatch may also include a second portion, wherein each body of theparticulate material of the second portion has a non-uniformly dispersedsecond phase, including for example, a “halo” arrangement of the secondphase within the body.

In other embodiments, the batch can include a plurality of particulatematerial, and more notably a particle-to-particle variation of thesecond phase of not greater than about 50%. Reference herein to aparticle-to-particle variation includes a standard deviation of thesecond phase within the particulate material of the batch, which may beobtained from a statistically relevant and random sampling of theparticulate material of the batch. Accordingly, a particle-to-particlevariation of the second phase can be a measure of the variation incontent of the second phase from particle-to-particle within the batch.In other embodiments, the particle-to-particle variation of the secondphase can be less, such as not greater than about 40%, not greater thanabout 30%, not greater than about 20%, not greater than about 15%, notgreater than about 10%, or even not greater than about 5%.

The body of the shaped abrasive particle can have a particulartwo-dimensional shape. For example, the body can have a two-dimensionalshape as viewed in a plane define by the length and width having apolygonal shape, ellipsoidal shape, a numeral, a Greek alphabetcharacter, Latin alphabet character, Russian alphabet character, complexshapes utilizing a combination of polygonal shapes and a combinationthereof. Particular polygonal shapes include triangular, rectangular,quadrilateral, pentagon, hexagon, heptagon, octagon, nonagon, decagon,any combination thereof. Other irregular polygonal shapes may also beutilized, including for example, star-shaped particles, cross-shapedparticles, truncated triangular-shaped particles, and the like.

FIG. 3A includes a perspective view illustration of an abrasive particlein accordance with one embodiment. Additionally, FIG. 3B includes across-sectional illustration of the abrasive particle of FIG. 3A. Thebody 301 includes an upper surface 303 a bottom major surface 304opposite the upper surface 303. The upper surface 303 and the bottomsurface 304 can be separated from each other by side surfaces 305, 306,and 307. As illustrated, the body 301 of the shaped abrasive particle300 can have a generally triangular shape as viewed in a plane of theupper surface 303. In particular, the body 301 can have a length(Lmiddle) as shown in FIG. 3B, which may be measured at the bottomsurface 304 of the body 301 and extending from a corner 313 through amidpoint 381 of the body 301 to a midpoint at the opposite edge 314 ofthe body. Alternatively, the body can be defined by a second length orprofile length (Lp), which is the measure of the dimension of the bodyfrom a side view at the upper surface 303 from a first corner 313 to anadjacent corner 312. Notably, the dimension of Lmiddle can be a lengthdefining a distance between a height at a corner (hc) and a height at amidpoint edge (hm) opposite the corner. The dimension Lp can be aprofile length along a side of the particle defining the distancebetween h1 and h2. Reference herein to the length can be reference toeither Lmiddle or Lp.

The body 301 can further include a width (w) that is the longestdimension of the body and extending along a side. The shaped abrasiveparticle can further include a height (h), which may be a dimension ofthe shaped abrasive particle extending in a direction perpendicular tothe length and width in a direction defined by a side surface of thebody 301. Notably, as will be described in more detail herein, the body301 can be defined by various heights depending upon the location on thebody. In specific instances, the width can be greater than or equal tothe length, the length can be greater than or equal to the height, andthe width can be greater than or equal to the height.

Moreover, reference herein to any dimensional characteristic (e.g., h1,h2, hi, w, Lmiddle, Lp, and the like) can be reference to a dimension ofa single particle of a batch, a median value, or an average valuederived from analysis of a suitable sampling of particles from a batch.Unless stated explicitly, reference herein to a dimensionalcharacteristic can be considered reference to a median value that is abased on a statistically significant value derived from a sample size ofsuitable number of particles of a batch of particles. Notably, forcertain embodiments herein, the sample size can include at least 40randomly selected particles from a batch of particles. A batch ofparticles may be a group of particles that are collected from a singleprocess run, and more particularly, may include an amount of shapedabrasive particles suitable for forming a commercial grade abrasiveproduct, such as at least about 20 lbs. of particles.

In accordance with an embodiment, the body 301 of the shaped abrasiveparticle can have a first corner height (hc) at a first region of thebody defined by a corner 313. Notably, the corner 313 may represent thepoint of greatest height on the body 301, however, the height at thecorner 313 does not necessarily represent the point of greatest heighton the body 301. The corner 313 can be defined as a point or region onthe body 301 defined by the joining of the upper surface 303, and twoside surfaces 305 and 307. The body 301 may further include othercorners, spaced apart from each other, including for example, corner 311and corner 312. As further illustrated, the body 301 can include edges314, 315, and 316 that can separated from each other by the corners 311,312, and 313. The edge 314 can be defined by an intersection of theupper surface 303 with the side surface 306. The edge 315 can be definedby an intersection of the upper surface 303 and side surface 305 betweencorners 311 and 313. The edge 316 can be defined by an intersection ofthe upper surface 303 and side surface 307 between corners 312 and 313.

As further illustrated, the body 301 can include a second midpointheight (hm) at a second end of the body, which can be defined by aregion at the midpoint of the edge 314, which can be opposite the firstend defined by the corner 313. The axis 350 can extend between the twoends of the body 301. FIG. 3B is a cross-sectional illustration of thebody 301 along the axis 350, which can extend through a midpoint 381 ofthe body along the dimension of length (Lmiddle) between the corner 313and the midpoint of the edge 314.

In accordance with an embodiment, the shaped abrasive particles of theembodiments herein, including for example, the particle of FIGS. 3A and3B can have an average difference in height, which is a measure of thedifference between hc and hm. For convention herein, average differencein height will be generally identified as hc−hm, however it is definedan absolute value of the difference and it will be appreciated thataverage difference in height may be calculated as hm-hc when the heightof the body 301 at the midpoint of the edge 314 is greater than theheight at the corner 313. More particularly, the average difference inheight can be calculated based upon a plurality of shaped abrasiveparticles from a suitable sample size, such as at least 40 particlesfrom a batch as defined herein. The heights hc and hm of the particlescan be measured using a STIL (Sciences et Techniques Industrielles de laLumiere-France) Micro Measure 3D Surface Profilometer (white light (LED)chromatic aberration technique) and the average difference in height canbe calculated based on the average values of hc and hm from the sample.

As illustrated in FIG. 3B, in one particular embodiment, the body 301 ofthe shaped abrasive particle may have an average difference in height atdifferent locations at the body. The body can have an average differencein height, which can be the absolute value of [hc−hm] between the firstcorner height (hc) and the second midpoint height (hm) is at least about20 microns. It will be appreciated that average difference in height maybe calculated as hm−hc when the height of the body 301 at a midpoint ofthe edge is greater than the height at an opposite corner. In otherinstances, the average difference in height [hc−hm], can be at leastabout 25 microns, at least about 30 microns, at least about 36 microns,at least about 40 microns, at least about 60 microns, such as at leastabout 65 microns, at least about 70 microns, at least about 75 microns,at least about 80 microns, at least about 90 microns, or even at leastabout 100 microns. In one non-limiting embodiment, the averagedifference in height can be not greater than about 300 microns, such asnot greater than about 250 microns, not greater than about 220 microns,or even not greater than about 180 microns. It will be appreciated thatthe average difference in height can be within a range between any ofthe minimum and maximum values noted above. Moreover, it will beappreciated that the average difference in height can be based upon anaverage value of hc. For example, the average height of the body at thecorners (Ahc) can be calculated by measuring the height of the body atall corners and averaging the values, and may be distinct from a singlevalue of height at one corner (hc). Accordingly, the average differencein height may be given by the absolute value of the equation [Ahc−hi].Furthermore, it will be appreciated that the average difference inheight can be calculated using a median interior height (Mhi) calculatedfrom a suitable sample size from a batch of shaped abrasive particlesand an average height at the corners for all particles in the samplesize. Accordingly, the average difference in height may be given by theabsolute value of the equation [Ahc−Mhi].

In particular instances, the body 301 can be formed to have a primaryaspect ratio, which is a ratio expressed as width:length, having a valueof at least 1:1. In other instances, the body can be formed such thatthe primary aspect ratio (w:1) is at least about 1.5:1, such as at leastabout 2:1, at least about 4:1, or even at least about 5:1. Still, inother instances, the abrasive particle can be formed such that the bodyhas a primary aspect ratio that is not greater than about 10:1, such asnot greater than 9:1, not greater than about 8:1, or even not greaterthan about 5:1. It will be appreciated that the body 301 can have aprimary aspect ratio within a range between any of the ratios notedabove. Furthermore, it will be appreciated that reference herein to aheight is the maximum height measurable of the abrasive particle. Itwill be described later that the abrasive particle may have differentheights at different positions within the body 101 of the abrasiveparticle 100.

In addition to the primary aspect ratio, the abrasive particle can beformed such that the body 301 comprises a secondary aspect ratio, whichcan be defined as a ratio of length:height, wherein the height is aninterior median height (Mhi). In certain instances, the secondary aspectratio can be within a range between about 5:1 and about 1:3, such asbetween about 4:1 and about 1:2, or even between about 3:1 and about1:2.

In accordance with another embodiment, the abrasive particle can beformed such that the body 301 comprises a tertiary aspect ratio, definedby the ratio width:height, wherein the height is an interior medianheight (Mhi). The tertiary aspect ratio of the body 101 can be within arange between about 10:1 and about 1.5:1, such as between 8:1 and about1.5:1, such as between about 6:1 and about 1.5:1, or even between about4:1 and about 1.5:1.

According to one embodiment, the body 301 of the shaped abrasiveparticle can have particular dimensions, which may facilitate improvedperformance. For example, in one instance, the body can have an interiorheight (hi), which can be the smallest dimension of height of the bodyas measured along a dimension between any corner and opposite midpointedge on the body. In particular instances wherein the body is agenerally triangular two-dimensional shape, the interior height (hi) maybe the smallest dimension of height (i.e., measure between the bottomsurface 304 and the upper surface 305) of the body for threemeasurements taken between each of the three corners and the oppositemidpoint edges. The interior height (hi) of the body of a shapedabrasive particle is illustrated in FIG. 3B. According to oneembodiment, the interior height (hi) can be at least about 28% of thewidth (w). The height (hi) of any particle may be measured by sectioningor mounting and grinding the shaped abrasive particle and viewing in amanner sufficient (e.g., light microscope or SEM) to determine thesmallest height (hi) within the interior of the body 301. In oneparticular embodiment, the height (hi) can be at least about 29% of thewidth, such as at least about 30%, or even at least about 33% of thewidth of the body. For one non-limiting embodiment, the height (hi) ofthe body can be not greater than about 80% of the width, such as notgreater than about 76%, not greater than about 73%, not greater thanabout 70%, not greater than about 68% of the width, not greater thanabout 56% of the width, not greater than about 48% of the width, or evennot greater than about 40% of the width. It will be appreciated that theheight (hi) of the body can be within a range between any of the abovenoted minimum and maximum percentages.

A batch of shaped abrasive particles, can be fabricated, wherein themedian interior height value (Mhi) can be controlled, which mayfacilitate improved performance. In particular, the median internalheight (hi) of a batch can be related to a median width of the shapedabrasive particles of the batch in the same manner as described above.Notably, the median interior height (Mhi) can be at least about 28%,such as at least about 29%, at least about 30%, or even at least about33% of the median width of the shaped abrasive particles of the batch.For one non-limiting embodiment, the median interior height (Mhi) of thebody can be not greater than about 80%, such as not greater than about76%, not greater than about 73%, not greater than about 70%, not greaterthan about 68% of the width, not greater than about 56% of the width,not greater than about 48% of the width, or even not greater than about40% of the median width. It will be appreciated that the median interiorheight (Mhi) of the body can be within a range between any of the abovenoted minimum and maximum percentages.

Furthermore, the batch of shaped abrasive particles may exhibit improveddimensional uniformity as measured by the standard deviation of adimensional characteristic from a suitable sample size. According to oneembodiment, the shaped abrasive particles can have an interior heightvariation (Vhi), which can be calculated as the standard deviation ofinterior height (hi) for a suitable sample size of particles from abatch. According to one embodiment, the interior height variation can benot greater than about 60 microns, such as not greater than about 58microns, not greater than about 56 microns, or even not greater thanabout 54 microns. In one non-limiting embodiment, the interior heightvariation (Vhi) can be at least about 2 microns. It will be appreciatedthat the interior height variation of the body can be within a rangebetween any of the above noted minimum and maximum values.

For another embodiment, the body of the shaped abrasive particle canhave an interior height (hi) of at least about 400 microns. Moreparticularly, the height may be at least about 450 microns, such as atleast about 475 microns, or even at least about 500 microns. In stillone non-limiting embodiment, the height of the body can be not greaterthan about 3 mm, such as not greater than about 2 mm, not greater thanabout 1.5 mm, not greater than about 1 mm, not greater than about 800microns. It will be appreciated that the height of the body can bewithin a range between any of the above noted minimum and maximumvalues. Moreover, it will be appreciated that the above range of valuescan be representative of a median interior height (Mhi) value for abatch of shaped abrasive particles.

For certain embodiments herein, the body of the shaped abrasive particlecan have particular dimensions, including for example, a width≧length, alength≧height, and a width≧height. More particularly, the body of theshaped abrasive particle can have a width (w) of at least about 600microns, such as at least about 700 microns, at least about 800 microns,or even at least about 900 microns. In one non-limiting instance, thebody can have a width of not greater than about 4 mm, such as notgreater than about 3 mm, not greater than about 2.5 mm, or even notgreater than about 2 mm. It will be appreciated that the width of thebody can be within a range between any of the above noted minimum andmaximum values. Moreover, it will be appreciated that the above range ofvalues can be representative of a median width (Mw) for a batch ofshaped abrasive particles.

The body of the shaped abrasive particle can have particular dimensions,including for example, a length (L middle or Lp) of at least about 0.4mm, such as at least about 0.6 mm, at least about 0.8 mm, or even atleast about 0.9 mm. Still, for at least one non-limiting embodiment, thebody can have a length of not greater than about 4 mm, such as notgreater than about 3 mm, not greater than about 2.5 mm, or even notgreater than about 2 mm. It will be appreciated that the length of thebody can be within a range between any of the above noted minimum andmaximum values. Moreover, it will be appreciated that the above range ofvalues can be representative of a median length (Ml), which may be moreparticularly, a median middle length (MLmiddle) or median profile length(MLp) for a batch of shaped abrasive particles.

The shaped abrasive particle can have a body having a particular amountof dishing, wherein the dishing value (d) can be defined as a ratiobetween an average height of the body at the corners (Ahc) as comparedto smallest dimension of height of the body at the interior (hi). Theaverage height of the body at the corners (Ahc) can be calculated bymeasuring the height of the body at all corners and averaging thevalues, and may be distinct from a single value of height at one corner(hc). The average height of the body at the corners or at the interiorcan be measured using a STIL (Sciences et Techniques Industrielles de laLumiere-France) Micro Measure 3D Surface Profilometer (white light (LED)chromatic aberration technique). Alternatively, the dishing may be basedupon a median height of the particles at the corner (Mhc) calculatedfrom a suitable sampling of particles from a batch. Likewise, theinterior height (hi) can be a median interior height (Mhi) derived froma suitable sampling of shaped abrasive particles from a batch. Accordingto one embodiment, the dishing value (d) can be not greater than about2, such as not greater than about 1.9, not greater than about 1.8, notgreater than about 1.7, not greater than about 1.6, or even not greaterthan about 1.5. Still, in at least one non-limiting embodiment, thedishing value (d) can be at least about 0.9, such as at least about 1.0.It will be appreciated that the dishing ratio can be within a rangebetween any of the minimum and maximum values noted above. Moreover, itwill be appreciated that the above dishing values can be representativeof a median dishing value (Md) for a batch of shaped abrasive particles.

The shaped abrasive particles of the embodiments herein, including forexample, the body 301 of the particle of FIG. 3A can have a bottomsurface 304 defining a bottom area (A_(b)). In particular instances thebottom surface 304 can be the largest surface of the body 301. Thebottom surface can have a surface area defined as the bottom area(A_(b)) that is greater than the surface area of the upper surface 303.Additionally, the body 301 can have a cross-sectional midpoint area(A_(m)) defining an area of a plane perpendicular to the bottom area andextending through a midpoint 381 of the particle. In certain instances,the body 301 can have an area ratio of bottom area to midpoint area(A_(b)/A_(m)) of not greater than about 6. In more particular instances,the area ratio can be not greater than about 5.5, such as not greaterthan about 5, not greater than about 4.5, not greater than about 4, notgreater than about 3.5, or even not greater than about 3. Still, in onenon-limiting embodiment, the area ratio may be at least about 1.1, suchas at least about 1.3, or even at least about 1.8. It will beappreciated that the area ratio can be within a range between any of theminimum and maximum values noted above. Moreover, it will be appreciatedthat the above area ratios can be representative of a median area ratiofor a batch of shaped abrasive particles.

Furthermore the shaped abrasive particles of the embodiments herein,including for example, the particle of FIG. 3B can have a normalizedheight difference of at least about 0.3. The normalized heightdifference can be defined by the absolute value of the equation[(hc−hm)/(hi)]. In other embodiments, the normalized height differencecan be not greater than about 0.26, such as not greater than about 0.22,or even not greater than about 0.19. Still, in one particularembodiment, the normalized height difference can be at least about 0.04,such as at least about 0.05, at least about 0.06. It will be appreciatedthat the normalized height difference can be within a range between anyof the minimum and maximum values noted above. Moreover, it will beappreciated that the above normalized height values can berepresentative of a median normalized height value for a batch of shapedabrasive particles.

In another instance, the body can have a profile ratio of at least about0.04, wherein the profile ratio is defined as a ratio of the averagedifference in height [hc−hm] to the length (Lmiddle) of the shapedabrasive particle, defined as the absolute value of [(hc−hm)/(Lmiddle)].It will be appreciated that the length (Lmiddle) of the body can be thedistance across the body 301 as illustrated in FIG. 3B. Moreover, thelength may be an average or median length calculated from a suitablesampling of particles from a batch of shaped abrasive particles asdefined herein. According to a particular embodiment, the profile ratiocan be at least about 0.05, at least about 0.06, at least about 0.07, atleast about 0.08, or even at least about 0.09. Still, in onenon-limiting embodiment, the profile ratio can be not greater than about0.3, such as not greater than about 0.2, not greater than about 0.18,not greater than about 0.16, or even not greater than about 0.14. Itwill be appreciated that the profile ratio can be within a range betweenany of the minimum and maximum values noted above. Moreover, it will beappreciated that the above profile ratio can be representative of amedian profile ratio for a batch of shaped abrasive particles.

According to another embodiment, the body can have a particular rakeangle, which may be defined as an angle between the bottom surface 304and a side surface 305, 306 or 307 of the body. For example, the rakeangle may be within a range between about 1° and about 80°. For otherparticles herein, the rake angle can be within a range between about 5°and 55°, such as between about 10° and about 50°, between about 15° and50°, or even between about 20° and 50°. Formation of an abrasiveparticle having such a rake angle can improve the abrading capabilitiesof the abrasive particle 100. Notably, the rake angle can be within arange between any two rake angles noted above.

According to another embodiment, the shaped abrasive particles herein,including for example the particles of FIGS. 3A and 3B can have anellipsoidal region 317 in the upper surface 303 of the body 301. Theellipsoidal region 317 can be defined by a trench region 318 that canextend around the upper surface 303 and define the ellipsoidal region317. The ellipsoidal region 317 can encompass the midpoint 381.Moreover, it is thought that the ellipsoidal region 317 defined in theupper surface can be an artifact of the forming process, and may beformed as a result of the stresses imposed on the mixture duringformation of the shaped abrasive particles according to the methodsdescribed herein.

In one aspect, the body can include a shaped abrasive particle having apercent flashing that may facilitate improved performance. Notably, theflashing defines an area of the particle as viewed along one side, suchas illustrated in FIG. 4, wherein the flashing can extend from a sidesurface of the body within the boxes 402 and 403. The flashing canrepresent tapered regions proximate to the upper surface and bottomsurface of the body. The flashing can be measured as the percentage ofarea of the body along the side surface contained within a box extendingbetween an innermost point of the side surface (e.g., 421) and anoutermost point (e.g., 422) on the side surface of the body. In oneparticular instance, the body can have a particular content of flashing,which can be the percentage of area of the body contained within theboxes 402 and 403 compared to the total area of the body containedwithin boxes 402, 403, and 404. According to one embodiment, the percentflashing (f) of the body can be at least about 10%. In anotherembodiment, the percent flashing can be greater, such as at least about12%, such as at least about 14%, at least about 16%, at least about 18%,or even at least about 20%. Still, in a non-limiting embodiment, thepercent flashing of the body can be not greater than about 45%, such asnot greater than about 40%, or even not greater than about 36%. It willbe appreciated that the percent flashing of the body can be within arange between any of the above minimum and maximum percentages.Moreover, it will be appreciated that the above flashing percentages canbe representative of an average flashing percentage or a median flashingpercentage for a batch of shaped abrasive particles.

The percent flashing can be measured by mounting the shaped abrasiveparticle on its side and viewing the body at the side to generate ablack and white image, such as illustrated in FIG. 4. A suitable programfor such includes ImageJ software. The percentage flashing can becalculated by determining the area of the body 401 in the boxes 402 and403 compared to the total area of the body as viewed at the side (totalshaded area), including the area in the center 404 and within the boxes.Such a procedure can be completed for a suitable sampling of particlesto generate average, median, and/or and standard deviation values.

A batch of particulate material including shaped abrasive particlesaccording to embodiments herein may exhibit improved dimensionaluniformity as measured by the standard deviation of a dimensionalcharacteristic from a suitable sample size. According to one embodiment,the shaped abrasive particles can have a flashing variation (Vf), whichcan be calculated as the standard deviation of flashing percentage (f)for a suitable sample size of particles from a batch. According to oneembodiment, the flashing variation can be not greater than about 5.5%,such as not greater than about 5.3%, not greater than about 5%, or notgreater than about 4.8%, not greater than about 4.6%, or even notgreater than about 4.4%. In one non-limiting embodiment, the flashingvariation (Vf) can be at least about 0.1%. It will be appreciated thatthe flashing variation can be within a range between any of the minimumand maximum percentages noted above.

The particulate material including shaped abrasive particles of theembodiments herein can have a height (hi) and flashing multiplier value(hiF) of at least 4000, wherein hiF=(hi)(f), an “hi” represents aminimum interior height of the body as described above and “f”represents the percent flashing. In one particular instance, the heightand flashing multiplier value (hiF) of the body can be greater, such asat least about 4500 micron %, at least about 5000 micron %, at leastabout 6000 micron %, at least about 7000 micron %, or even at leastabout 8000 micron %. Still, in one non-limiting embodiment, the heightand flashing multiplier value can be not greater than about 45000 micron%, such as not greater than about 30000 micron %, not greater than about25000 micron %, not greater than about 20000 micron %, or even notgreater than about 18000 micron %. It will be appreciated that theheight and flashing multiplier value of the body can be within a rangebetween any of the above minimum and maximum values. Moreover, it willbe appreciated that the above multiplier value can be representative ofa median multiplier value (MhiF) for a batch of shaped abrasiveparticles.

The particulate material including shaped abrasive particles of theembodiments herein can have a dishing (d) and flashing (F) multipliervalue (dF) as calculated by the equation dF=(d)(F), wherein dF is notgreater than about 90%, “d” represents the dishing value, and “f”represents the percentage flashing of the body. In one particularinstance, the dishing (d) and flashing (F) multiplier value (dF) of thebody can be not greater than about 70%, such as not greater than about60%, not greater than about 55%, not greater than about 48%, not greaterthan about 46%. Still, in one non-limiting embodiment, the dishing (d)and flashing (F) multiplier value (dF) can be at least about 10%, suchas at least about 15%, at least about 20%, at least about 22%, at leastabout 24%, or even at least about 26%. It will be appreciated that thedishing (d) and flashing (F) multiplier value (dF) of the body can bewithin a range between any of the above minimum and maximum values.Moreover, it will be appreciated that the above multiplier value can berepresentative of a median multiplier value (MdF) for a batch of shapedabrasive particles.

The particulate material including shaped abrasive particles of theembodiments herein can have a height and dishing ratio (hi/d) ascalculated by the equation hi/d=(hi)/(d), wherein hi/d is not greaterthan about 1000, “hi” represents a minimum interior height as describedabove, and “d” represents the dishing of the body. In one particularinstance, the ratio (hi/d) of the body can be not greater than about 900microns, not greater than about 800 microns, not greater than about 700microns, or even not greater than about 650 microns. Still, in onenon-limiting embodiment, the ratio (hi/d), can be at least about 10microns, such as at least about 50 microns, at least about 100 microns,at least about 150 microns, at least about 200 microns, at least about250 microns, or even at least about 275 microns. It will be appreciatedthat the ratio (hi/d) of the body can be within a range between any ofthe above minimum and maximum values. Moreover, it will be appreciatedthat the above height and dishing ratio can be representative of amedian height and dishing ratio (Mhi/d) for a batch of shaped abrasiveparticles.

The particulate material can be formed such that the body includes acrystalline material, and more particularly, a polycrystalline material.Notably, the polycrystalline material can include abrasive grains. Inone embodiment, the body can be essentially free of an organic material,including for example, a binder. More particularly, the body can consistessentially of a polycrystalline material.

As noted herein, the particulate material can be an abrasive material.As such, the particulate material may be deployed in various manners foruse in abrasive articles. For example, the particulate material may bepart of a fixed abrasive article such as a coated abrasive article,bonded abrasive article, and a combination thereof. In particularinstances, the particulate material can be coupled to a bond material,and further coupled to a backing or substrate via the bond material. Thebond material may include compositions such as vitrified materials,ceramic materials, metal alloy, organic material, a resin, a polymer,and a combination thereof. In at least one instance, the particulatematerial can be part of a coated abrasive forming a single layer ofabrasive particles coupled to a backing.

FIG. 5 includes an illustration of a portion of an abrasive articleincluding particulate material in accordance with an embodiment. Inparticular, the abrasive article of FIG. 5 includes a coated abrasive500 having a substrate 501 and at least one adhesive layer overlying asurface of the substrate 501. The adhesive layer can include one or morelayers of material, including for example, a make coat 503 and/or a sizecoat 504. The coated abrasive 500 can include abrasive particulatematerial 510, which can include shaped abrasive particles 505 of theembodiments herein and a second type of abrasive particulate material507 in the form of diluent abrasive particles having a random shape,which may not necessarily be shaped abrasive particles. The abrasiveparticulate material 507 can also be representative of the particulatematerial of the embodiments herein, including any combination offeatures of the embodiments herein. The make coat 503 can be overlyingthe surface of the substrate 501 and surrounding at least a portion ofthe shaped abrasive particles 505 and second type of abrasiveparticulate material 507. The size coat 504 can be overlying and bondedto the shaped abrasive particles 505 and second type of abrasiveparticulate material 507 and the make coat 503.

According to one embodiment, the substrate 501 can include an organicmaterial, inorganic material, and a combination thereof. In certaininstances, the substrate 501 can include a woven material. However, thesubstrate 501 may be made of a non-woven material. Particularly suitablesubstrate materials can include organic materials, including polymers,and particularly, polyester, polyurethane, polypropylene, polyimidessuch as KAPTON from DuPont, paper. Some suitable inorganic materials caninclude metals, metal alloys, and particularly, foils of copper,aluminum, steel, and a combination thereof.

A polymer formulation may be used to form any of a variety of layers ofthe abrasive article such as, for example, the frontfill, the pre-sizecoat, the make coat, the size coat, and/or the supersize coat. When usedto form the frontfill, the polymer formulation may generally include apolymer resin, fibrillated fibers (preferably in the form of pulp),filler material, and other optional additives. Suitable formulations forsome frontfill embodiments can include material such as a phenolicresin, wollastonite filler, defoamer, surfactant, a fibrillated fiber,and a balance of water. Suitable polymeric resin materials includecurable resins selected from thermally curable resins including phenolicresins, urea/formaldehyde resins, phenolic/latex resins, as well ascombinations of such resins. Other suitable polymeric resin materialsmay also include radiation curable resins, such as those resins curableusing electron beam, UV radiation, or visible light, such as epoxyresins, acrylated oligomers of acrylated epoxy resins, polyester resins,acrylated urethanes and polyester acrylates and acrylated monomersincluding monoacrylated, multiacrylated monomers. The formulation canalso comprise a non-reactive thermoplastic resin binder which canenhance the self-sharpening characteristics of the deposited abrasivecomposites by enhancing the erodability. Examples of such thermoplasticresin include polypropylene glycol, polyethylene glycol, andpolyoxypropylene-polyoxyethene block copolymer, etc. Use of a frontfillon the backing can improve the uniformity of the surface, for suitableapplication of the make coat and improved application and orientation ofshaped abrasive particles in a predetermined orientation.

The make coat 503 can be applied to the surface of the substrate 501 ina single process, or alternatively, the abrasive particulate material510 can be combined with a make coat 503 material and applied as amixture to the surface of the substrate 501. Suitable materials of themake coat 503 can include organic materials, particularly polymericmaterials, including for example, polyesters, epoxy resins,polyurethanes, polyamides, polyacrylates, polymethacrylates, poly vinylchlorides, polyethylene, polysiloxane, silicones, cellulose acetates,nitrocellulose, natural rubber, starch, shellac, and mixtures thereof.In one embodiment, the make coat 503 can include a polyester resin. Thecoated substrate can then be heated in order to cure the resin and theabrasive particulate material to the substrate. In general, the coatedsubstrate 501 can be heated to a temperature of between about 100° C. toless than about 250° C. during this curing process.

The abrasive particulate material 510 can include shaped abrasiveparticles according to embodiments herein. In particular instances, theabrasive particulate material 510 may include different types of shapedabrasive particles. The different types of shaped abrasive particles candiffer from each other in composition, two-dimensional shape,three-dimensional shape, size, and a combination thereof as described inthe embodiments herein. As illustrated, the coated abrasive 500 caninclude a shaped abrasive particle 505 having a generally triangulartwo-dimensional shape.

The other type of abrasive particles 507 can be diluent particlesdifferent than the shaped abrasive particles 505. For example, thediluent particles can differ from the shaped abrasive particles 505 incomposition, two-dimensional shape, three-dimensional shape, size, and acombination thereof. For example, the abrasive particles 507 canrepresent conventional, crushed abrasive grit having random shapes. Theabrasive particles 507 may have a median particle size less than themedian particle size of the shaped abrasive particles 505.

After sufficiently forming the make coat 503 with the abrasiveparticulate material 510, the size coat 504 can be formed to overlie andbond the abrasive particulate material 510 in place. The size coat 504can include an organic material, may be made essentially of a polymericmaterial, and notably, can use polyesters, epoxy resins, polyurethanes,polyamides, polyacrylates, polymethacrylates, poly vinyl chlorides,polyethylene, polysiloxane, silicones, cellulose acetates,nitrocellulose, natural rubber, starch, shellac, and mixtures thereof.

FIGS. 6-11 include exemplary abrasive particulate material havingspecific contours and defining shaped abrasive particles, which canincorporate the compositions described herein. As shown in FIG. 6, theshaped abrasive particle 600 may include a body 601 that is generallyprismatic with a first end face 602 and a second end face 604. Further,the shaped abrasive particle 600 may include a first side face 610extending between the first end face 602 and the second end face 604. Asecond side face 612 may extend between the first end face 602 and thesecond end face 604 adjacent to the first side face 610. As shown, theshaped abrasive particle 600 may also include a third side face 614extending between the first end face 602 and the second end face 604adjacent to the second side face 612 and the first side face 610.

As depicted in FIG. 6, the shaped abrasive particle 600 may also includea first edge 620 between the first side face 610 and the second sideface 612. The shaped abrasive particle 600 may also include a secondedge 622 between the second side face 612 and the third side face 614.Further, the shaped abrasive particle 600 may include a third edge 624between the third side face 614 and the first side face 612.

As shown, each end face 602, 604 of the shaped abrasive particle 600 maybe generally triangular in shape, or may be a truncated triangularshape. Each side face 610, 612, 614 may be generally rectangular inshape. Further, the cross section of the shaped abrasive particle 600 ina plane parallel to the end faces 602, 604 can be generally triangular.It will be appreciated that while the cross-sectional shape of theshaped abrasive particle 600 through a plane parallel to the end faces602, 604 is illustrated as being generally triangular, other shapes arepossible, including any polygonal shapes, for example a quadrilateral, apentagon, a hexagon, a heptagon, an octagon, a nonagon, a decagon, etc.Further, the cross-sectional shape of the shaped abrasive particle maybe convex, non-convex, concave, or non-concave. While the particle isillustrated as having a prismatic shape, it will be appreciated that theshape may be altered, such that it is a thin body having generallytriangular end faces 602 and 604 and a dimension of thickness extendingbetween the end faces 602 and 604, which can be the smallest dimensionof the particle.

FIG. 7 includes an illustration of a shaped abrasive particle accordingto another embodiment. As depicted, the shaped abrasive particle 700 mayinclude a body 701 that may include a central portion 702 that extendsalong a longitudinal axis 704. A first radial arm 706 may extendoutwardly from the central portion 702 along the length of the centralportion 702. A second radial arm 708 may extend outwardly from thecentral portion 702 along the length of the central portion 702. A thirdradial arm 710 may extend outwardly from the central portion 702 alongthe length of the central portion 702. Moreover, a fourth radial arm 712may extend outwardly from the central portion 702 along the length ofthe central portion 702. The radial arms 706, 708, 710, 712 may beequally spaced around the central portion 702 of the shaped abrasiveparticle 700.

As shown in FIG. 7, the first radial arm 706 may include a generallyarrow shaped distal end 720. The second radial arm 708 may include agenerally arrow shaped distal end 722. The third radial arm 710 mayinclude a generally arrow shaped distal end 724. Further, the fourthradial arm 712 may include a generally arrow shaped distal end 726.

FIG. 7 also indicates that the shaped abrasive particle 700 may beformed with a first void 730 between the first radial arm 706 and thesecond radial arm 708. A second void 732 may be formed between thesecond radial arm 708 and the third radial arm 710. A third void 734 mayalso be formed between the third radial arm 710 and the fourth radialarm 712. Additionally, a fourth void 736 may be formed between thefourth radial arm 712 and the first radial arm 706.

As shown in FIG. 7, the shaped abrasive particle 700 may include alength 740, a height 742, and a width 744. In a particular aspect, thelength 740 is greater than the height 742 and the height 742 is greaterthan the width 744. In a particular aspect, the shaped abrasive particle700 may define a primary aspect ratio that is the ratio of the length740 to the height 742 (length:width). Further, the shaped abrasiveparticle 700 may define a secondary aspect ratio that is the ratio ofthe height 742 to the width 744 (width:height). Finally, the shapedabrasive particle 700 may define a tertiary aspect ratio that is theratio of the length 740 to the width 742 (length:height).

According to one embodiment, the shaped abrasive particles can have aprimary aspect ratio of at least about 1:1, such as at least about1.1:1, at least about 1.5:1, at least about 2:1, at least about 2.5:1,at least about 3:1, at least about 3.5:1, at least 4:1, at least about4.5:1, at least about 5:1, at least about 6:1, at least about 7:1, atleast about 8:1, or even at least about 10:1.

In another instance, the shaped abrasive particle can be formed suchthat the body has a secondary aspect ratio of at least about 0.5:1, suchas at least about 0.8:1, at least about 1:1, at least about 1.5:1, atleast about 2:1, at least about 2.5:1, at least about 3:1, at leastabout 3.5:1, at least 4:1, at least about 4.5:1, at least about 5:1, atleast about 6:1, at least about 7:1, at least about 8:1, or even atleast about 10:1.

Furthermore, certain shaped abrasive particles can have a tertiaryaspect ratio of at least about 1:1, such as at least about 1.5:1, atleast about 2:1, at least about 2.5:1, at least about 3:1, at leastabout 3.5:1, at least 4:1, at least about 4.5:1, at least about 5:1, atleast about 6:1, at least about 7:1, at least about 8:1, or even atleast about 10:1.

Certain embodiments of the shaped abrasive particle 700 can have a shapewith respect to the primary aspect ratio that is generally rectangular,e.g., flat or curved. The shape of the shaped abrasive particle 700 withrespect to the secondary aspect ratio may be any polyhedral shape, e.g.,a triangle, a square, a rectangle, a pentagon, etc. The shape of theshaped abrasive particle 700 with respect to the secondary aspect ratiomay also be the shape of any alphanumeric character, e.g., 1, 2, 3,etc., A, B, C. etc. Further, the contour of the shaped abrasive particle700 with respect to the secondary aspect ratio may be a characterselected from the Greek alphabet, the modern Latin alphabet, the ancientLatin alphabet, the Russian alphabet, any other alphabet, or anycombination thereof. Further, the shape of the shaped abrasive particle700 with respect to the secondary aspect ratio may be a Kanji character.

FIGS. 8-9 depict another embodiment of a shaped abrasive particle thatis generally designated 800. As shown, the shaped abrasive particle 800may include a body 801 that has a generally cube-like shape. It will beappreciated that the shaped abrasive particle may be formed to haveother polyhedral shapes. The body 801 may have a first end face 802 anda second end face 804, a first lateral face 806 extending between thefirst end face 802 and the second end face 804, a second lateral face808 extending between the first end face 802 and the second end face804. Further, the body 801 can have a third lateral face 810 extendingbetween the first end face 802 and the second end face 804, and a fourthlateral face 812 extending between the first end face 802 and the secondend face 804.

As shown, the first end face 802 and the second end face 804 can beparallel to each other and separated by the lateral faces 806, 808, 810,and 812, giving the body a cube-like structure. However, in a particularaspect, the first end face 802 can be rotated with respect to the secondend face 804 to establish a twist angle 814. The twist of the body 801can be along one or more axes and define particular types of twistangles. For example, as illustrated in a top-down view of the body inFIG. 9 looking down the longitudinal axis 880 defining a length of thebody 801 on the end face 802 parallel to a plane defined by the lateralaxis 881 extending along a dimension of width of the body 801 and thevertical axis 882 extending along a dimension of height of the body 801.According to one embodiment, the body 801 can have a longitudinal twistangle 814 defining a twist in the body 801 about the longitudinal axissuch that the end faces 682 and 804 are rotated relative to each other.The twist angle 814, as illustrated in FIG. 9 can be measured as theangle between a tangent of a first edge 822 and a second edge 824,wherein the first edge 822 and second edge 824 are joined by and share acommon edge 826 extending longitudinally between two of the lateralfaces (810 and 812). It will be appreciated that other shaped abrasiveparticles can be formed to have twist angles relative to the lateralaxis, the vertical axis, and a combination thereof. Any of such twistangles can have a value as described herein.

In a particular aspect, the twist angle 814 is at least about 1°. Inother instances, the twist angle can be greater, such as at least about2°, at least about 5°, at least about 8°, at least about 10°, at leastabout 12°, at least about 15°, at least about 18°, at least about 20°,at least about 25°, at least about 30°, at least about 40°, at leastabout 50°, at least about 60°, at least about 70°, at least about 80°,or even at least about 90°. Still, according to certain embodiments, thetwist angle 814 can be not greater than about 360°, such as not greaterthan about 330°, such as not greater than about 300°, not greater thanabout 270°, not greater than about 230°, not greater than about 200°, oreven not greater than about 180°. It will be appreciated that certainshaped abrasive particles can have a twist angle within a range betweenany of the minimum and maximum angles noted above.

Further, the body may include an opening that extends through the entireinterior of the body along one of the longitudinal axis, lateral axis,or vertical axis.

FIG. 10 includes an illustration of another embodiment of a shapedabrasive particle. As shown, the shaped abrasive particle 1000 mayinclude a body 1001 having a generally pyramid shape with a generallytriangle shaped bottom face 1002. The body can further include sides1016, 1017, and 1018 connected to each other and the bottom face 1002.It will be appreciated that while the body 1001 is illustrated as havinga pyramidal polyhedral shape, other shapes are possible, as describedherein/

According to one embodiment, the shaped abrasive particle 1000 may beformed with a hole 1004 (i.e., and opening) that can extend through atleast a portion of the body 1001, and more particularly may extendthrough an entire volume of the body 1001. In a particular aspect, thehole 1004 may define a central axis 1006 that passes through a center ofthe hole 1004. Further, the shaped abrasive particle 1000 may alsodefine a central axis 1008 that passes through a center 1030 of theshaped abrasive particle 1000. It may be appreciated that the hole 1004may be formed in the shaped abrasive particle 1000 such that the centralaxis 1006 of the hole 1004 is spaced apart from the central axis 1008 bya distance 1010. As such, a center of mass of the shaped abrasiveparticle 1000 may be moved below the geometric midpoint 1030 of theshaped abrasive particle 1000, wherein the geometric midpoint 1030 canbe defined by the intersection of a longitudinal axis 1009, lateral axis1011, and the central axis (i.e., lateral axis) 1008. Moving the centerof mass below the geometric midpoint 1030 of the shaped abrasive graincan increase the likelihood that the shaped abrasive particle 1000 landson the same face, e.g., the bottom face 1002, when dropped, or otherwisedeposited, onto a backing, such that the shaped abrasive particle 1000has a predetermined, upright orientation.

In a particular embodiment, the center of mass is displaced from thegeometric midpoint 1030 by a distance that can be at least about 0.05the height (h) along a longitudinal axis 1009 of the body 1002 defininga height. In another embodiment, the center of mass may be displacedfrom the geometric midpoint 1030 by a distance of at least about 0.1(h),such as at least about 0.15(h), at least about 0.18(h), at least about0.2(h), at least about 0.22(h), at least about 0.25(h), at least about0.27(h), at least about 0.3(h), at least about 0.32(h), at least about0.35(h), or even at least about 0.38(h). Still, the center of mass ofthe body 1001 may be displaced a distance from the geometric midpoint1030 of no greater than 0.5(h), such as no greater than 0.49 (h), nogreater than 0.48(h), no greater than 0.45(h), no greater than 0.43(h),no greater than 0.40(h), no greater than 0.39(h), or even no greaterthan 0.38(h). It will be appreciated that the displacement between thecenter of mass and the geometric midpoint can be within a range betweenany of the minimum and maximum values noted above.

In particular instances, the center of mass may be displaced from thegeometric midpoint 1030 such that the center of mass is closer to abase, e.g., the bottom face 1002, of the body 1001, than a top of thebody 1001 when the shaped abrasive particle 1000 is in an uprightorientation as shown in FIG. 10.

In another embodiment, the center of mass may be displaced from thegeometric midpoint 1030 by a distance that is at least about 0.05 thewidth (w) along a lateral axis 1008 of the of the body 1001 defining thewidth. In another aspect, the center of mass may be displaced from thegeometric midpoint 1030 by a distance of at least about 0.1(w), such asat least about 0.15(w), at least about 0.18(w), at least about 0.2(w),at least about 0.22(w), at least about 0.25(w), at least about 0.27(w),at least about 0.3(w), or even at least about 0.35(w). Still, in oneembodiment, the center of mass may be displaced a distance from thegeometric midpoint 1030 no greater than 0.5(w), such as no greater than0.49 (w), no greater than 0.45(w), no greater than 0.43(w), no greaterthan 0.40(w), or even no greater than 0.38(w). It will be appreciatedthat the center of mass can be displaced a distance from the geometricmidpoint along the lateral axis within a range between any of theminimum and maximum values noted above.

In another embodiment, the center of mass may be displaced from thegeometric midpoint 1030 along the longitudinal axis 1009 by a distance(Dl) of at least about 0.05 the length (l) of the body 1001. Accordingto a particular embodiment, the center of mass may be displaced from thegeometric midpoint by a distance of at least about 0.1(l), such as atleast about 0.15(l), at least about 0.18(l), at least about 0.2(l), atleast about 0.25(l), at least about 0.3(l), at least about 0.35(l), oreven at least about 0.38(l). Still, for certain abrasive particles, thecenter of mass can be displaced a distance no greater than about 0.5(l),such as no greater than about 0.45(l), or even no greater than about0.40(l). It will be appreciated that the center of mass can be displaceda distance from the geometric midpoint along the longitudinal axis by adistance within a range between any of the minimum and maximum valuesnoted above.

FIG. 11 includes an illustration of a shaped abrasive particle accordingto an embodiment. The shaped abrasive grain 1100 may include a body 1101including a base surface 1102 and an upper surface 1104 separated fromeach other by one or more side surfaces 1110, 1112, and 1114. Accordingto one particular embodiment, the body 1101 can be formed such that thebase surface 1102 has a planar shape different than a planar shape ofthe upper surface 1104, wherein the planar shape is viewed in the planedefined by the respective surface. For example, as illustrated in theembodiment of FIG. 11, the body 1101 can have base surface 1102generally have a circular shape and an upper surface 1104 having agenerally triangular shape. It will be appreciated that other variationsare feasible, including any combination of shapes at the base surface1102 and upper surface 1104.

EXAMPLE 1

A first sample of particulate material (S1) is made according to thefollowing procedures. First, lanthanum nitrate hexahydrate, phosphoricacid, and deionized water are obtained. A calcined, raw material powderof alumina is obtained and the pore volume is measured using BET and theamount of water that is absorbed by a 10 g sample of the raw materialpowder to determine saturation and over-saturation conditions for theraw material powder. The raw material is commercially available asCatapal B from Sasol Corp.

The additive is formed, which includes a first component of a phosphoricacid and a second component of lanthanum nitrate salt solution. Each ofthe components is formed based on an intended amount of second phasethat is desired in the finally-formed particulate material. Thecomponents are in the form of solutions.

The raw material powder is impregnated with the phosphoric acidcomponent by dispersing the solution on the raw material powder andstirring the mixture. The mixture is dried for at least 8 hours at 95°C. in air.

After drying the raw material impregnated with the phosphoric acidcomponent, the available pore volume for the lanthanum nitrate saltcomponent is calculated based on the first component addition. A molarratio of approximately 1:1 of La to P is used to calculate theconcentration of the lanthanum nitrate salt to be added to the dried rawmaterial. The lanthanum nitrate salt component is then dispersed ontothe dried material while stirring for impregnation into thealumina-based raw material. The mixture is dried for at least 8 hours at95° C. in air.

The mixture including the first and second components is sintered in arotary kiln at a temperature of approximately 1450° C. for a time of 10minutes in air. The sintered particulate material had a density of 97.5%theoretical density, a specific surface area of 0.1 m²/g, approximately97% of a first phase of alpha alumina, approximately 1.0 wt % of asecond phase of monazite (LaPO₄), approximately 1.3 wt % of a thirdphase of a lanthanum aluminate compound (i.e., MgLaAl₁₁O₁₉), and aremainder of impurity materials.

Particles according to Example 1 were made and analyzed. FIGS. 12A and12B provide SEM images of a particulate material formed according toExample 1. As illustrated, the exemplary body 1201 includes anon-uniform distribution of the second phase at a peripheral region 1201of the body. The particulate material demonstrates a non-uniformdistribution of the second phase and the third phase, and in particular,the second phase is preferentially distributed in a peripheral region1202, distinct from the central region 1203. Moreover, the third phaseis preferentially distributed in the peripheral region 1202.

The abrasive particles of FIGS. 12A and 12B demonstrate remarkable andunexpected improvement in grinding capabilities compared to conventionalgrains. FIG. 13 includes a plot of specific grinding energy versuscumulative material removed for a grinding test on a workpiece of 304stainless steel operated as a dry plunge grinding operation at amaterial removal rate of 4 inch³/min inch, grinding in short intervalsremoving 0.2 inch³/interval, at a wheel speed of 7500 sfpm. Asillustrated, the particulate material of sample S1 demonstratedincreased cumulative material removed at a consistently lower specificgrinding energy compared to state-of-the-art abrasive materials. Inparticular, the comparative examples using the same belt architecture(e.g., backing material, make coat material, size coat material, etc.)included conventional sample 1 (CS1), commercially available as HiPAL133-1 from Saint-Gobain Abrasives, Inc. and conventional sample 2 (CS2),commercially available from 3M as 321 abrasive grain.

EXAMPLE 2

A second sample (S2) of particulate material is made according toExample 1, but the component of lanthanum nitrate salt is added first,and thereafter, the component of phosphoric acid is added. Theparticulate material of sample S2 had a density of 97.5% theoreticaldensity, a specific surface area of 0.1 m²/g, approximately 98% of afirst phase of alpha alumina, approximately 1.1 wt % of a second phaseof monazite (LaPO₄), approximately 0.7 wt % of a third phase of alanthanum aluminate compound (i.e., MgLaAl₁₁O₁₉), and a minor content ofimpurities.

Particles according to Example 2 were made and analyzed. FIG. 14includes a SEM image of particulate material formed according to Example2. As illustrated, the exemplary body 1401 includes a non-uniformdistribution of the second phase at a peripheral region 1402 of the body1401. After analysis, it was determined the particulate material has anon-uniform distribution of the second phase and the third phase, and inparticular, the second phase is preferentially distributed in aperipheral region 1402 and the third phase is preferentially distributedin a central region 1403.

EXAMPLE 3

A third sample (S3) of particulate material is made according to anembodiment, and in particular utilizes a doping procedure. The dopingprocedure includes forming an additive in the form of a mixtureincluding La nitrate hexahydrate in water with phosphoric acid. Achemical reaction occurred, forming hydrated monazite (rhabdophane) as aprecipitate. The mixture containing the hydrated monazite is then mixedwith a precursor raw material powder of Example 1. The precursor rawmaterial powder of Example 1 is formed from boehmite commerciallyavailable as Catapal B from Sasol Corp. that is incorporated into amixture including 30% solids (boehmite), 1 wt % seed material (alphaalumina) for the total weight of the boehmite, and 7 wt % nitric acidfor the total weight of the boehmite. The mixture is in the form of aslurry using water as the liquid carrier that gels under ambientconditions. The additive can be added to the slurry or gel to dope theprecursor raw material. Thereafter, the precursor raw material with theadditive can be dried at 95° C., crushed and calcined at 1000° C.Thereafter, the material can further be sintered according to theconditions of Example 1.

The particulate material of sample S3 has a density of approximately97.5% theoretical density, a specific surface area of about 0.1 m²/g,approximately 96.5% of a first phase of alpha alumina, approximately 1.4wt % of a second phase of monazite (LaPO₄), and approximately 2.1 wt %of a third phase of a lanthanum aluminate compound (i.e., MgLaAl₁₁O₁₉),and a minor content of impurities.

Particles according to Example 3 were made and analyzed. FIG. 15includes a SEM picture of an exemplary particulate material formedaccording to Example 3. As illustrated, the body 1501 includes asubstantially, uniform distribution of the second phase throughout thebody 1501, and generally no evidence of a “halo” region isdistinguishable.

EXAMPLE 4

A fourth sample (S4) of particulate material is made according to anembodiment, and in particular, utilizes the same procedure used to formthe particulate material S1, however the process is directed toimpregnation of shaped abrasive particles. Accordingly, the raw materialpowder is in the form of green (i.e., unsintered) shaped abrasiveparticles, which have been dried after being formed. The first componentis added to the green shaped abrasive particles, and the particles arecalcined, and the second component is added to the calcined particles.The calcined particles having both components of the additiveimpregnated in the body are sintered. FIG. 16 includes an illustrationof an exemplary particulate material formed according to Example 4. Asillustrated, the body 1601 includes a non-uniform distribution of thesecond phase at a peripheral region 1602 of the body, generally defininga “halo” region within the body 1601 that is generally distinct from acentral region 1603 within the interior of the body 1601.

The particulate material of sample S4 has a density of approximately97.5% theoretical density, approximately 97.6% of a first phase of alphaalumina, approximately 0.9 wt % of a second phase of monazite (LaPO₄),and approximately 1.5 wt % of a third phase of a lanthanum aluminatecompound (i.e., MgLaAl₁₁O₁₉), and a minor content of impurities.

EXAMPLE 5

A fifth sample (S5), a sixth sample (S6), and a seventh sample (S7) wereformed according to Example 4, thus forming triangular shaped abrasiveparticles with different contents of monazite. The fifth sample S5includes 3.8 wt % monazite and approximately 2.5 wt % lanthanumaluminate, sample S6 has 8.3 wt % monazite and approximately 2.5 wt %lanthanum alumina, and sample S7 has 12.9 wt % monazite andapproximately 1.5 wt % lanthanum alumina. Each of the samples had anaverage crystalline size of alpha alumina of less than about 1 micron.The samples were tested according to the grinding test detailed inExample 1. FIG. 17 includes a plot of specific grinding energy versuscumulative material removed for a grinding test using samples S5, S6,and S7. The grinding test was performed on a workpiece of 304 stainlesssteel operated as a dry plunge grinding operation at a material removalrate of 4 inch³/min inch, grinding in short intervals removing 0.2inch³/interval, at a wheel speed of 7500 sfpm. As illustrated, samplesS5, S6, and S7 demonstrated different grinding performance as comparedto each other.

The present application represents a departure from the state of theart. While the industry has recognized that alumina materials may havecertain additives, such as zirconia, magnesia, lanthanum, and calcia,and raw material mineral additives including a combination of suchelements, such as monazite, the industry has not recognized thesignificance of the combination of features disclosed herein. Notably,the particulate material of the embodiments herein can be formed throughunique processes that can result in a combination of unique features,including but not limited to composition, additives, morphology,two-dimensional shape, three-dimensional shape, distribution of phases,difference in height, difference in height profile, flashing percentage,height, dishing, half-life change of specific grinding energy, and acombination thereof. And in fact, particulate material of embodimentsherein has proven to result in remarkable and unexpected performance.

The above-disclosed subject matter is to be considered illustrative, andnot restrictive, and the appended claims are intended to cover all suchmodifications, enhancements, and other embodiments, which fall withinthe true scope of the present invention. Thus, to the maximum extentallowed by law, the scope of the present invention is to be determinedby the broadest permissible interpretation of the following claims andtheir equivalents, and shall not be restricted or limited by theforegoing detailed description.

The Abstract of the Disclosure is provided to comply with Patent Law andis submitted with the understanding that it will not be used tointerpret or limit the scope or meaning of the claims. In addition, inthe foregoing Detailed Description, various features may be groupedtogether or described in a single embodiment for the purpose ofstreamlining the disclosure. This disclosure is not to be interpreted asreflecting an intention that the claimed embodiments require morefeatures than are expressly recited in each claim. Rather, as thefollowing claims reflect, inventive subject matter may be directed toless than all features of any of the disclosed embodiments. Thus, thefollowing claims are incorporated into the Detailed Description, witheach claim standing on its own as defining separately claimed subjectmatter.

What is claimed is:
 1. A particulate material having a body including afirst phase comprising alumina and a second phase comprising an oxidecompound, wherein the oxide compound comprises phosphorus and a rareearth element, wherein the body comprises a greater content of thesecond phase within a peripheral region of the body as compared to acontent of the second phase within a central region of the body whereinthe body is a shaped abrasive particle.
 2. A particulate material havinga body including a first phase comprising alumina and a second phasecomprising phosphorus and a rare earth element, wherein the bodycomprises a greater content of the second phase within a peripheralregion of the body as compared to a content of the second phase within acentral region of the body, and wherein the body further comprises athird phase, and wherein the third phase comprises lanthanum aluminate.3. The particulate material according to claim 2, wherein the bodyincludes at least 0.5 to 30 wt % of the third phase for the total weightof the body.
 4. The particulate material according to claim 2, whereinthe second phase comprises monazite.
 5. The particulate materialaccording to claim 2, wherein the body comprises a ratio [W3/W2],wherein W3 represents a weight percent of the third phase within thebody and W2 represents a weight percent of the second phase within thebody, and wherein the ratio [W3/W2] is at least about 1.5.
 6. Theparticulate material according to claim 2, wherein the body comprises aratio [G1/G3], wherein G1 represents an average grain size of the firstphase and G3 represents an average grain size of the third phase, andwherein the ratio [G1/G3 ] is in a range between about 0.2 and
 5. 7. Theparticulate material according to claim 2, wherein the third phase isdisposed within grains of the first or second phases.
 8. The particulatematerial according to claim 1, wherein the body includes at least 0.5 to30 wt % of the second phase for the total weight of the body.
 9. Theparticulate material according to claim 1, wherein the second phasecomprises LaPO₄.
 10. The particulate material according to claim 1,wherein the particulate material is part of a fixed abrasive articleselected from the group consisting of a coated abrasive article and abonded abrasive article.
 11. The particulate material according to claim1, wherein the body comprises a two-dimensional shape selected from thegroup consisting of triangular, quadrilateral, rectangular, trapezoidal,pentagonal, heptagonal, hexagonal, and octagonal.
 12. The particulatematerial according to claim 2, wherein the body is a shaped abrasiveparticle.
 13. The particulate material according to claim 1, wherein thefirst phase has an average grain size of not greater than about 500 μmand the second phase has an average grain size of not greater than about1 micron.
 14. The particulate material according to claim 2, wherein thebody comprises a greater content of the third phase within a peripheralregion of the body as compared to a content of the third phase within acentral region of the body.
 15. The particulate material according toclaim 2, wherein the content of the third phase is uniformly dispersedin the body.
 16. The particulate material according to claim 1, whereinthe content of the second phase in the peripheral region is greater thanhalf of the total amount of second phase in the body based on the weightof the second phase.
 17. The particulate material according to claim 1,wherein the first phase includes at least 70 to 99.5 wt % alumina forthe total weight of the first phase.
 18. A particulate material having abody including a first phase comprising alumina and a second phasecomprising phosphorus and a rare earth element, wherein the bodycomprises a greater content of the second phase within a peripheralregion of the body as compared to a content of the second phase within acentral region of the body, and wherein the body is a shaped abrasiveparticle.
 19. The particulate material according to claim 18, whereinthe second phase comprises LaPO₄.
 20. The particulate material accordingto claim 18, wherein the particulate material is part of a fixedabrasive article selected from the group consisting of a coated abrasivearticle and a bonded abrasive article.